California Department of Transportation
Transportation Economics
California Bypass Study
The Economic Impacts of Bypasses
Volume 1: Planning Reference
FINAL REPORT
System Metrics Group, Inc.
In association with
Cambridge Systematics, Inc.
Economic Development Research Group, Inc.
HLB Decision Economics, Inc.
Judd Associates
May 2006
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Table of Contents
INTRODUCTION
THEORETICAL RESEARCH
CALIFORNIA CASE STUDIES
HIGHWAY BYPASS IMPACT ( HBI) MODEL
REFERENCES
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INTRODUCTION
By rerouting traffic around the main streets of small towns, highway bypasses can
provide a number of direct transportation benefits, such as diverting unwanted traffic,
increasing roadway safety, reducing travel delays, and improving local access for
people and goods. While these traffic impacts are well- understood, bypasses also have
the potential to impact local economies. Area business owners may fear potential
reductions in sales, while civic leaders may look forward to redeveloping downtown or
promoting development along the new bypass.
California is planning a number of bypasses over the next few years, particularly as the
State Highway System matures and bypasses help to relieve congestion in local
communities. Understanding the potential economic impacts is particularly important
since local stakeholders often raise economic considerations to support or oppose
proposed bypasses. Although the California Division of Highways conducted small
studies in the 1950s, there have not been many studies of the economic impacts of
California bypasses in recent years.
The California Department of Transportation ( Caltrans) sponsored the California
Bypass Study to improve basic knowledge about the impacts of bypasses on small- town
economies. The study included an investigation into the economic impacts of recent
bypasses nationally and in California. This research is intended to foster better
planning and construction of highway bypass projects by allowing the State to:
• Develop a better understanding of the economic, fiscal and other closely
related social and environmental impacts on communities affected by
highway bypasses
• Identify factors that can adversely affect the economic health of
communities and the development of a standard methodology for the
analysis of the economic impacts of bypass projects
• Promote better project planning, design and implementation of bypass
projects on a statewide basis to minimize adverse economic impacts and
to maximize beneficial outcomes of such projects
• Consider fully “ community livability,” “ context sensitive solutions” and
“ environmental justice” issues in project planning and implementation
as they relate to proposed bypass projects.
Although bypasses are planned for California communities of all sizes, the study
focused on small towns, where bypasses are more likely to affect the local economy. In
these settings, disruptions to a few local businesses can result in large impacts. Smaller
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communities also tend to have fewer alternative highway routes, making the addition
of bypasses more significant.
As part of the California Bypass Study, the project team investigated previously
constructed highway bypasses, both in California and other states, on a before- and- after
( with- and- without) basis. Information about other states comes primarily from
literature reviews, while direct field visits and published data provide substantial
information about the California experience.
The project team produced a database of four previously constructed and ten planned
bypasses in California small towns. From a review of theoretical research and field
research in California, the team developed best practices and lessons learned to help
Caltrans planners and engineers plan for future bypasses. The project team also
developed a spreadsheet tool that helps forecast potential economic impacts for
planned bypasses. The Highway Bypass Impact ( HBI) Model provides a range of
possible impacts for use in discussions with the local community. The project included
extensive field work and site visits to ensure that the results reflect the views of local
stakeholders and is context sensitive.
Summary Findings
This report describes what the project team learned about the economic impacts of
bypasses and is intended to serve as a reference handbook for Caltrans planners and
engineers. In general, bypasses impact the local economy as a function of the type of
traffic addressed. Businesses in communities with heavy local traffic or with through
traffic that does not stop will not be impacted. Communities that provide services to
pass- through traffic are more likely to be impacted.
Caltrans planners and engineers, local business leaders, and local governments should
consider several issues in planning and designing bypasses:
What types of towns are impacted economically?
• Highway- oriented towns have a much harder time transitioning their
economies after bypasses are constructed than those that cater to local
residents or offer tourist attractions.
• Towns that serve as residential communities or as tourist destinations
can benefit from reduced traffic and improved safety as a result of
highway bypasses. Local government and the business community may
need to engage in complementary efforts, such as marketing, downtown
redevelopment, additional parking, and sidewalk improvements, to take
advantage.
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• Towns that serve regional markets by providing services, such as big
box retail, automobile dealers, department stores, or hospitals, may
experience little or no economic impacts. If a bypass provides better
access to regional services, the local economy may actually improve as
the town expands its regional draw.
• Towns with other economic bases, such as government employment,
mining, agriculture, manufacture, etc. are not likely to be economically
impacted by bypasses.
Which businesses are impacted?
• Gas stations and quick service or fast food restaurants cater the most to
pass- through traffic. They are most likely to be impacted by the
diversion of traffic due to bypasses.
• Other visitor- serving businesses, such as motels, art galleries, antique
stores, and curio shops, cater more to visitors attracted to the
community as a destination rather than those simply passing through.
These businesses are less likely to be negatively impacted by bypasses
and may find that business improves if the downtown is turned into a
destination.
• Regionally serving businesses, such as big box retail and departments
stores, may benefit from improved access.
• Businesses that serve local residents, such as drug stores, banks, and
grocery stores are generally not impacted by bypasses.
What other impacts occur?
• Bypasses often have a short- term ( and negative) impact on the local
economy, but retail sales often improve in the longer term. However,
some communities may never fully recover.
• The construction of a bypass may also provide an opportunity for
revitalization of the local community.
• Bypasses are often promoted as improving pedestrian safety along Main
Street. Since traffic accidents involving pedestrians are relatively rare
events, Caltrans collision statistics may not reflect improved safety.
However, bypasses may improve the perception of safety, which is a
benefit in its own right.
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What design features are most important?
• Visibility. Negative economic impacts ( losses of customers and sales)
are likely to be small for businesses that remain visible from bypasses.
In some cases, the goal of making downtowns visible from bypasses
may conflict with the desire to protect communities from noise and
visual impacts. Caltrans can provide some “ visibility” for businesses
through signage.
• Distance from downtown. Bypasses located close to existing
downtowns are less likely to hurt local economies. Travelers may be
able to see businesses and access times are shorter.
• Direct access. Highway interchanges can provide direct access from
bypasses to downtowns and existing businesses. However,
interchanges can also encourage the development of competition to
existing businesses by offering new “ prime” locations.
• Time savings. The difference in travel time between the old route and
the new bypass determines how many vehicles ( and potential
customers) divert to the bypass.
What can Caltrans do?
• In the field research, local communities offered several suggestions on
how Caltrans can provide signs that may mitigate negative economic
impacts. For example:
– Caltrans could provide signs indicating services are available
at the next exit. Some businesses have offered to pay for
signs, but Caltrans districts have raised a concern whether the
Department can be involved in “ advertising” for specific
businesses.
– Caltrans could designate the existing route as a “ scenic or
historic” route to encourage tourist traffic. However, this
must fit within the Department’s guidelines for such
designation.
– A bypass could be designated as a bypass route, while the
original route retains the State Route designation. This may
conflict with the State’s policy to avoid parallel routes.
• The large lag between initial planning and engineering and construction
may discourage businesses and residents from believing that a bypass
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will eventually be built. The availability of funding and regional
priorities are beyond Caltrans’ control, but Districts should try to keep
the public actively involved, remind residents and businesses about
planned bypasses, and help the community plan for the transition.
• Caltrans can work with local governments and chambers of commerce
to encourage businesses to plan early for bypasses. Businesses may
choose to market to local residents, change their line of business, or
relocate.
• Caltrans should continue to recognize the need to conduct early
analyses of impacts on tribal governments, facilities, and economies.
Districts need to consult in the earliest planning stages and on an on-going
basis with the Native American communities as critical
stakeholders for transportation planning.
What can local communities do?
• Local communities can take advantage of reduced general and truck
traffic along Main Street by engaging in redevelopment activities, such
as main street programs, the provision of benches, planting and
improved sidewalks, economic development incentives and grants,
providing parking facilities, etc.
• Communities can provide roads, utilities, and other infrastructure at
interchanges along the bypass to attract businesses and encourage the
relocation of traffic- dependant businesses, such as gas stations and fast
food restaurants.
• If a bypass remains outside of the local jurisdiction, a town can annex
territory to make sure that any economic development remains inside
the local tax base. Alternatively, the local community can zone the area
or withhold utilities and infrastructure, so developments that compete
with downtown do not occur.
• Local governments and chambers of commerce can work with local
businesses to develop business plans that take into account the change
in traffic due to bypasses.
• The community should have a vision of how a bypass will be integrated
into the local environment ( e. g., transportation flow, redevelopment,
visual impact, economics, etc.).
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What are other issues to consider?
• Caltrans planners and engineers should recognize that the motivations
for a particular bypass may differ between Caltrans and the local
community ( public and government):
– For Caltrans, the focus is on through traffic and safety issues.
Caltrans typically builds bypasses to implement infrastructure
plans ( convert conventional highways to expressways or
freeways), address mobility issues ( improve traffic flow,
improve level of service for inter- regional traffic, address
operational issues), or mitigate safety problems.
– For the local community, the focus is on local traffic and the
impacts on downtown. The local community often expects
bypasses to address problems with truck traffic ( eliminate
noise, dirt/ dust, and safety perceptions), mobility ( improve
level of serve, help local circulation, reduce idling noise in
downtown), and traffic control ( improve appearance of traffic
control measures, hold community festivals, etc.).
• Local communities often resist accepting relinquishments until
significant improvements are made. However, the relinquishment of
Main Street to local control can be an enticement in some cases.
• Traffic signals can address local circulation issues in rural communities,
but they may not address long- term issues with through traffic.
• Bypasses may be unable to solve local circulation problems. Caltrans
planners and engineers need to consider whether congestion needs to be
addressed through State Highway bypasses or improvements in local
roads.
Report Organization
The rest of this report is organized in the following chapters, which provide additional
resources for Caltrans planners and engineers:
• Theoretical Research – This section summarizes academic studies of the
economic impacts of bypasses. It outlines community characteristics,
bypass design features, and behavioral factors that influence the
economic impacts of bypasses.
• California Case Studies – This section describes the California bypasses
visited as part of the California Bypass Study. It provides an overview
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of the bypasses, data collected, and what the project team learned.
Caltrans planners and engineers can use this information to anticipate
potential impacts of future bypasses. A second volume of this report
provides individual case studies for planners or engineers wanting to
identify similar situations.
• Highway Bypass Impact ( HBI) Model – This section provides a brief
overview of the HBI Model for planners and engineers. The emphasis is
on helping planners and engineers determine whether the model is an
appropriate tool for a given analysis. The section describes how the
model was developed, how it works, what it estimates, and how results
can be interpreted. Detailed technical documentation and a user’s guide
with instructions on using the model are available as separate reports.
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THEORETICAL RESEARCH
This section summarizes theoretical research that may be of interest to Caltrans
planners and engineers. While studies of highway bypass impacts on local economies
began to proliferate in the late 1980s, studies were available almost as soon as highway
bypasses were constructed. For example, the California Division of Highways
conducted a series of economic studies from 1949 to 1951 that examined the impact of
the then new high- speed freeways and bypasses. Most of these studies compared
trends in retail sales for bypassed communities with those for comparable areas.
Although the methodology is similar to many recent studies, the early studies could not
anticipate later trends of suburbanization, urban sprawl, retail relocation, and highway
congestion. These factors make current studies more difficult to conduct and often
more detailed methodologically.
In recent years, a number of national studies have examined the impacts of bypasses on
local communities. There have also been several syntheses of the literature. For
example, a National Cooperative Highway Research Program ( NCHRP) Synthesis of
Practice study uncovered a bibliography of over 100 highway bypass studies in the
United States, Europe, and Australia. While the situations of California communities
may differ from those in other countries and other parts of the United States, this
literature is relevant for uncovering themes applicable to California. Exhibit 1 lists
some of the relevant recent research on highway bypasses.
The next several sections outline findings from theoretical literature. The purpose is to
highlight lessons learned in earlier studies. The report identifies key factors and
economic impacts that Caltrans planners and engineers should consider when planning
and designing California bypasses. A later chapter provides additional findings from
field research conducted in California.
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Exhibit 1: Recent Case Studies of Highway Bypasses
Reference Study Area( s) Methodology Summary of Impacts
Collins and
Weisbrod ( 2000)
Danville, Virginia
I- 785 Bypass
Individual case study
Before- and- after
comparison
Reduction in downtown truck traffic; increase in
local vehicles. Overall: no evidence of negative
impacts on downtown businesses. Major impact
on new industrial sites near bypass interchanges.
Collins and
Weisbrod ( 2000)
Richmond, Virginia
I- 295 Bypass
Individual case study
Before- and- after
comparison
No reduction in downtown traffic. Bypass opened
sites for development in suburban ring:
considerable industrial development, major
regional shopping malls located near bypass
interchanges, some residential development.
Collins and
Weisbrod ( 2000)
Fort Wayne,
Indiana
I- 469 Bypass
Individual case study
Before- and- after
comparison
Significant volume of truck traffic diverted. Little
development at interchanges. Bypass is in rural
areas with limited water and sewer capacity.
Collins and
Weisbrod ( 2000)
Appleton,
Wisconsin
Route 441 Bypass
Individual case study
Before- and- after
comparison
Major retail development – big box stores - at
bypass interchanges. Also: about 100 acres of
industrial land developed; and some office space
in suburban locations.
Economic
Development
Research Group
( 2000)
Roanoke, Virginia
I- 73 Alignments
( Central, East,
West)
Review and analysis
of local area and
project
characteristics.
Projections for three
alternatives
Three alternatives have positive and negative
impacts. Positive: opening of industrial sites at
new interchanges, improved traffic conditions and
increased tourism. Negative: threat to city
businesses, displacement of existing businesses.
Risks include insufficient sites for highway access
and future development and costs of sprawl.
HLB Decision
Economics Inc.
( 2002)
Imperial Valley
Brawley Bypass
and I- 8/ Imperial
Avenue
Interchange
Review and analysis
of local area and
proj. characteristics.
Risk Analysis,
Projections of
Economic
Development
Benefits
The study found that four factors are critical to the
identification of projects with true development
potential. These factors include local
engagement, integration of project design,
development accessible and incremental
forecasting framework; and implementation of risk
analysis.
HLB Decision
Economics Inc.
( 2001)
Lewistown,
Montana. US 87
and US 191
Bypass
Economic feasibility
analysis using
transportation
modeling output,
Benefit cost analysis
and risk analysis
The findings of this study determined that a
bypass in Northeast Lewistown is not a feasible
alternative. The findings were based on a
comprehensive benefit- cost analysis in a risk
analysis framework.
Rogers and
Marshment
( 2000)
Stonewall and
other small, rural
towns in Oklahoma
Econometric analysis
and anecdotal
evidence
Bypass had no significant effect on already
declining small town business district. No
businesses relocated from old to bypass route; no
new businesses were established along new
route.
Wells and
Farnworth ( 2001)
Iowa, various
communities
Interviews with
business owners and
city leaders
Decline in sales for service stations, convenience
stores, small cafes, and motels, much smaller than
anticipated. Few businesses opened on or moved
to locations near bypass. Residents of bypassed
towns “ happy” with the bypass.
Purposes of Highway Bypasses
According to the Caltrans Design and Traffic Manual, a highway bypass is “ an arterial
highway that permits traffic to avoid part or all of an urban area.” The manual lists
several factors that Caltrans planners and engineers should review when considering
bypasses of State Highway routes. These factors are summarized below.
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Route Functionality and Quantitative Factors
• The major function the route serves as part of the State Highway System
and its classification is an indication of the route’s importance to various
types of travel. The route needs to be: functionally classified as a
Principal Arterial, on the National Highway System, on the
Interregional Road System ( state), or identified as a Surface
Transportation Assistance Act ( STAA) or Truck Terminal Access Route
for larger trucks. Focus Routes ( the ten routes and combination of
routes in the Interregional Transportation Strategic Plan for priority
improvements for interregional mobility) are included as demonstrating
additional route importance.
• Amount of current and projected future delay to the traveling public for
people and goods movement through the area, including the duration of
recurrent, non- recurrent, and seasonality or event- based ( major
destination concerts and promotional events) delay.
• Numbers of large trucks ( defined as having five or more axles) and
origins/ destinations ( through trips versus local delivery or
distribution).
• Disruption to town economic center and quality of life from current
routing.
• Availability and location of services to travelers ( food, lodging, car
repair, etc).
Qualitative Factors
• Inclusion and priority in the Regional Transportation Plan
• Evidence of continuing support ( sustained history) by the City
Council/ Board of Supervisors
• Contribution of regional and other funds considering funds available to
the area
• Willingness of the City or County to include the bypass route in the land
use element of the General Plan upon route adoption for corridor
protection and compatible zoning
• Availability of reasonable bypass routing alternatives considering
degree of build out of area, topography, and sensitive habitats or
preserves.
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Nationally, the bypassing of small and mid- sized towns started almost as soon as the
Federal Aid Highway Act of 1956 passed. The Interstate Highway program introduced
the American public and industry to the convenience of high speed automobile and
truck transportation, which led to the construction of highway bypasses around cities
and towns to maintain highway speeds for through traffic.
Theoretical research indicates that three issues have motivated the proposing, planning,
and constructing of highway bypasses across the nation:
• Upgrading existing roadway conditions. These include safety
considerations, such as attempts to lower collision rates and reduce
conflicts between trucks, automobiles, bicyclists and pedestrians, as well
as updates of substandard roadway to current highway standards for
design speed and access management. A new bypass may also
straighten point- to- point highway routing and improve user mobility.
• Adding capacity for accommodating actual or anticipated traffic volumes. This
is particularly apparent when congestion lowers highway speeds,
creates difficult driving conditions for through and local traffic, and
inhibits pedestrians from crossing streets. Sometimes bypasses are
motivated by the need to increase capacity for traffic with regional
destinations or to provide added highway capacity for anticipated
increases in traffic. Bypasses may facilitate goods movement by
allowing trucks to avoid traffic lights and downtown congestion.
Bypasses may also improve levels of service and control access to
industrial areas or other major destinations.
• Enhancing the “ quality of life” in bypassed communities. In the studies,
quality of life generally refers to safety, including residents’ concerns
about downtown traffic congestion and perceptions of pedestrian safety.
Quality of life enhancements often include improving traffic flows in
downtowns, such as reducing overall traffic or rerouting truck traffic for
the benefit of pedestrians and local traffic. A related objective for
developing bypasses is the relocation of trucks and a significant portion
of through traffic from downtown tourist destinations to increase the
vitality of central business districts. Similar goals for bypasses are
reductions in noise and air pollution, improved shopping environments,
and additional residential development.
These three reasons overlap and any combination of them can enter into the decision to
develop a particular bypass.
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Nature of Bypass Literature
Studies generally examine the impacts of highway bypasses around smaller cities and
towns. Usually, the studies focus only on the community being bypassed, although
some studies try to assess how other locations may benefit. Impacts are generally
measured in terms of employment, sales, or the number of businesses at a city or project
level. The analyses tend to focus on retail or service businesses, especially in traffic-oriented
sectors. The studies compare traffic volumes before and after construction on
the bypassed and new routes.
The hypothesis is that a one- time economic change occurs, although some studies have
looked at the longer- term evolution of impacts. The more nuanced studies review how
town economies restructure from retail to office or service centers, how tourist
economics expand, or how residential markets flourish.
In reviewing bypass studies, Caltrans planners and engineers will find that they include
one or more of the following types of analysis:
• Qualitative Case Studies. Interviews and surveys are conducted with
residents, community leaders, and local business leaders to gauge their
opinions. This approach often involves a review of the “ before and
after” business mix in downtowns and economic changes that can be
attributed to bypasses. An example of such a link is the removal of
trucks leading to growth in local tourism, increased residential
development, or the loss or relocation of downtown businesses.
• Data- Driven Case Studies. These are “ before and after” comparisons
based largely on population, employment and tax records from state or
federal sources such as the US Census. Bypass studies are frequently
supplemented with local quantitative data collection ( i. e., windshield
surveys and business surveys) as well as qualitative interview data.
• Statistical Analysis. These bypasses studies gather statistical information
about a series of bypasses rather than focus on specific communities.
The studies make generalizations using regression modeling or other
statistical techniques. Sometimes, findings are supplemented with
interviews to compare statistical findings with local impressions.
• Contextual Factors. In these studies, changes in the local economy are
placed in the context of non- transportation factors and local economic
shifts underway prior to the bypass. Bypasses may exacerbate economic
trends but are not considered to be responsible for the economic change
in downtowns. For example, several studies cite cases where the
downtowns are losing retail share and reorganizing into office centers
before the bypasses were built.
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The most informative literature combines two or more approaches. Statistical analyses
do take into account specific circumstances when developing overall findings. To make
up for this, investigators often complement quantitative data with interviews when
conducting these studies.
The studies tend to use a number of specific terms that Caltrans planners and engineers
may not be familiar with. These include:
• Economic base – the set of industries that provide the “ engine” or basis
for the local economy. For example, Silicon Valley is driven by the high
tech industry while Bakersfield exists to support agriculture. Small
California towns also have economic bases.
• Pass- though traffic – traffic that travels through a community to other
destinations. Other terms may be used interchangeably, such as
through traffic or pass- by traffic. This report uses all three terms.
• Visitor serving businesses – retail industries that cater to visitors staying
in the community. Examples include: motels, art galleries, museums,
wineries, and tourist shops.
• Pass- by serving businesses - retail industries that provide services to
pass- through traffic. Examples include: fast food restaurants and gas
stations. Note that local residents may also use these businesses, but
some establishments may be more oriented to travelers than others.
• Local serving businesses – retail industries that tend to serve the local
population and not travelers. Examples include: drugs stores and
banks.
• Central business district ( CBD) – the downtown of a community.
• Bypassed area – the section of highway and surrounding businesses and
residences that are bypassed. This often includes the downtown that
had formerly been served by the State Highway.
• Main Street – the primary route through a community and its
downtown. This often refers to the adopted route of a State Highway
prior to construction of a bypass.
Recent Research
This section summarizes for Caltrans planners and engineers some of the recent
academic articles on highway bypasses. The lessons learned from these articles are
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summarized in the sections that follow and the information below is for the more
technically inclined.
Wisconsin was one of the first states in recent years to study the economic impacts of
bypasses extensively. The Wisconsin Department of Transportation ( DOT)
commissioned a series of bypass studies in the late 1980s through the 1990s, including:
Highway Bypasses: Wisconsin Communities Share Their Experiences ( 1988), The Economic
Impacts of Highway Bypasses on Communities ( 1998), and US Highway 10 Relocation
Alternatives Economic Impact Analysis ( 1999).
In January 1998, the Wisconsin DOT published a study of the economic impacts of 17
small Wisconsin communities bypassed since 1980. The population of these
communities ranged from about 300 to 30,000 people. The study used economic data,
traffic counts, mapping, interviews, media research, and site visits to compare the 17
bypassed communities to 14 similar (“ control”) communities without bypasses.
The Wisconsin DOT study found that, over the long term, average traffic levels on the
“ old routes” in medium and large bypassed communities were close to or higher than
pre- bypass counts. Continued strong economic activity in those communities provided
opportunities for retail trade to flourish. Community residents and businesspeople
viewed bypasses as beneficial, while understanding that the bypasses cause changes in
the local economy to be addressed proactively. The communities identified several
benefits of bypasses and associated, including: improved traffic flow, reduced
congestion, less truck traffic, and opportunities for planned development. The authors
concluded that highway bypasses had little adverse impact on overall economic activity
in most communities, although bypasses had a greater potential to hurt the economies
of communities with populations less than 2,000.
In a 1994 study, Gillis and Casavant provided case studies of state routes bypassing main
streets in three small towns in eastern Washington. The case studies summarized
changes in the communities using data from interviews with community leaders,
business leaders and government officials as well as population and retail data from
state sources. Sales tax data provided a time series indicating the magnitude of retail
activities. Gillis and Casavant concluded that the negative impacts of bypasses were
smaller for downtown business districts with well- developed local customer bases than
those dependent on drive- by traffic. They also noted that bypass routes that improve
access to trading centers open new opportunities in small towns.
Rogers and Marshment ( 2001) identified and analyzed bypasses in Oklahoma to predict
the impacts of proposed bypasses along US- 70. Only three bypassed areas were
investigated and just one involved both a “ before and after” analysis. Since statistical
inferences could not be drawn from such a small sampling, Rogers and Marshment
compared the bypasses cities to a control group of communities with demographic
features and highways similar to the selected bypassed communities. Rogers and
Marshment examined a number of factors in the case studies, including population, sales
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tax, number of nearby State Highways and US routes, and retail trade. Using a method
comparable to Gillis and Casavant, they used sales tax revenues as a proxy for measuring
retail activities. Rogers and Marshment also conducted site visits to count business
establishments and collect qualitative data.
The Oklahoma study accounted for significant economic indicators and non- highway
related factors, including environmental regulations. The study also placed economic
performance in the context of energy- related factors, including regulation of
underground storage tanks and changes within the national oil and gas industry. While
these factors may be important factors in Oklahoma, they are less critical in states
without significant oil and gas exploration.
Andersen et. al. developed econometric models that incorporated data on retail sales,
gasoline sales, restaurant sales, and service receipts to analyze the economic base,
changes in business volume, and related economic impacts of highway bypasses on six
small Texas cities. Similar to Rogers and Marshment, the authors developed the analysis
with control communities and buttressed the quantitative results with site visits. The
study concluded that the economic impacts of highway bypasses on rural small cities
are not uniform and appeared to be minor in most cases. Econometric models showed
that bypasses generally brought small, but statistically significant, decreases in business
volume. Cluster analysis highlighted the importance of the existing economic base.
Interviews revealed that local perceptions were not necessarily negative. Those
interviewed cited bypass construction as one of many factors contributing to the overall
economic performance of cities. After initial commercial downturns, the bypasses often
led to the reorientation of businesses to local customers. Business and political leaders
frequently played important roles in the evolution of the cities after bypasses opened.
Through the National Cooperative Highway Research Program ( NCHRP), Buffington
and Womack ( 1995) surveyed 47 state DOTs and six Canadian provinces. They did not
conduct their own interviews and relied on secondary data. The study concentrated on
impacts in the areas bypassed and along the new bypasses. The overall assessment of
economic impacts in bypassed areas was inconclusive, although traffic- serving
businesses ( e. g., gas stations, restaurants, and motels) were the most likely to be hurt.
The authors concluded that declines seen in bypassed areas were attributable to
unrelated economic trends, which may have been hastened by the bypasses. Although
the study examined slightly larger towns ( a population threshold of 5,000 people
compared to 2,000 people), Buffington and Womack confirmed the findings in Gillis/
Casavant that population is an important indicator of community sensitivity to
economic impacts.
The NCHRP report shows that highway- serving business activity declined in 18 of 61
cases. Overall, ten of the 141 bypasses communities studied had negative impacts.
Seven out of ten were in small communities ( which accounted for 71 of the 141 total).
However, the data taken from surveys and past studies were not uniform. In assessing
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bypass impacts in the United Stats and Canada, the authors concluded that overall
positive impacts may be connected with communities’ ability to extend political
boundaries ( and taxation) to encompass new development along bypasses.
Similar to Buffington and Womack, researchers at the University of Kentucky ( Thompson,
Miller and Roenker, 2001) assessed the impacts of bypasses in Kentucky on both
bypassed areas and land near the new bypasses. The authors looked at eight bypasses
and established a pairing of bypass communities with similar communities. They
combined statistical methods with site visits and interviews to gather opinions as well
as quantitative data.
Thompson, Miller and Roenker reported findings in the aggregate and did not write
individual case studies for the eight sites. Interviews were summarized and reported
by community in an appendix. Thompson et. al. considered several variables, including
retail trade, population, quality of building stock, traffic congestion, land use and
environment. The mean 1990 population for the communities studied was about 4,000.
Much of the analysis centered on county- wide changes, so positive and negative local
impacts might have balanced. Analyses conducted at the local level showed that the
reallocation of retail from downtowns to bypass areas stemmed from new retail, not
relocation of existing businesses. Moreover, bypasses tended to reallocate office space
away from the bypassed areas. The authors noted that vacancies averaged 18.4 percent
for downtowns with bypasses compared to 10.9 percent for the paired central business
districts ( CBDs) without bypasses. However, the majority of downtown business
owners interviewed believed that the construction of bypasses had either positive or
insignificant impacts on local retail and service industries. The researchers stated that
findings were limited due to the small sample size ( eight communities).
Hartegen, et. al. ( 1991) provides insight on how bypasses might attract new development
or dislocate development from bypassed communities. The study includes a statistical
analysis of 22 interchanges in North Carolina and 63 nationally to illustrate the roles of
traffic volume, distance from downtown, and prevalence of water and sewer in
attracting motels, gas stations, fast food and sit- down restaurants and spurring housing
development.
Burress ( 1996) reviews some of the economic impacts of bypasses on 21 small Kansas
towns. Similar to the Wisconsin findings, he found that in the long term, bypasses do
not have significantly negative effects on the local economy. Most counties and many
towns may have benefited in the long term from the construction of bypasses. While
not all travel- related firms in bypassed towns were impacted negatively, bypasses
probably did have transitory impacts on selected travel- oriented businesses, including
restaurants, bars, motels, and service stations. Burress suggested that areas primarily
oriented to travel- related services might experience severe impacts and require
economic restructuring. Mirroring findings from the Oklahoma studies, the Kansas
study found that national and regional economic and population trends were more
important than bypass construction in determining economic effects.
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In a 1991 study for the Iowa Department of Transportation, Anderson and Otto ( 1991)
examined 11 rural communities with highway bypasses. Populations of the
communities ranged from 673 to nearly 7,900 people. The study found that the benefits
of improved traffic flow around the communities did not appear to be offset by
aggregate losses in retail sales. The authors share Burress’ conclusion that service
stations, convenience stores, motels, small cafes are most likely to experience declines
associated with new bypass construction.
Anderson and Otto also considered local perceptions of bypass impacts. They concluded
that several positive externalities were associated with bypasses: reduced traffic
congestion, fewer collisions, and increased sales attributed to the reduced congestion
and easier parking. They also found that the discontent of local merchants with the
bypasses increased with the distance between the bypass and the local central business
district. A majority of respondents supported the bypasses and most merchants agreed
that traffic volume and noise had decreased since the bypasses were built.
In 1988, Wisconsin DOT profiled the impacts of bypasses in Rice Lake and Sturgeon Bay
through local interviews and local surveys. Both communities were major waterfront
tourist destinations. As a result, removing truck traffic from these towns was beneficial
to the local economies. Retail trade increased in both towns and average daily traffic on
both old and new bypass routes increased.
The economic benefit of bypasses for tourist destinations is also highlighted in a pair of
Australian case studies by the Canberra Bureau of Transport and Communications
Economics ( 1994). The Bureau compared a bypass in a small, “ cute” tourist- oriented
town with a bypass in a larger non- tourist community, where a number of
establishments served through traffic. The bypass in Berrima ( population 425)
improved the town’s tourist appeal by reducing traffic and eliminating through truck
traffic. The result was a pleasant, pedestrian- oriented tourist community. The study
noted the growth in new bed and breakfasts, gift shops and restaurants. In contrast,
Mittagon ( population 4,240) did not have a tourist economy and saw a decline in
business activity, including gas stations, motels and fast food restaurants. The study
used interviews and surveys, statistical analyses, and public economic data.
Economic Development Research Group ( 2000) conducted an analysis of bypass routes in
medium- sized cities using interviews, supplemented by traffic data and publicly
available economic data, to determine before and after impacts of bypasses. Like the
Hartegen studies, Economic Development Research Group compares the impacts of
bypasses on older communities with the land- use changes near the new bypasses.
Across the case studies, bypasses frequently led to positive changes by removing heavy
truck traffic from downtowns and opening additional industrial sites along the new
routes. This attracted new, outside investment. The negative impacts included
increased low density commercial and residential development that led to additional
environmental and infrastructure costs.
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Factors Influencing Economic Impacts
Caltrans planners and engineers should realize that highway bypass studies tell a
consistent story. They indicate new highways seldom devastate or save downtowns.
Shifts in traffic patterns cause some businesses to close or relocate, but they also have
the potential to create new business opportunities in the bypassed downtown areas.
For business districts already draw local customers or are destinations for visitors, a
reduction in downtown traffic congestion is most likely to strengthen the downtown.
Like most issues in economics, consumer behavior governs how highway bypasses
impact downtown economies.
For Caltrans planners and engineers, most of the factors related to bypasses can be
placed into one of five categories:
• Spatial Context ( Land Pattern and Bypass Design)
• Land Use and Development Factors in Bypassed Area and Near Bypass
• Characteristics of Local Economy ( Business Mix in Pre- Bypass
Communities)
• Traffic Characteristic ( Pre- Bypass Origin- Destination and Trip Purpose)
• Demographics.
Planners and engineers should also think about a sixth category, environmental factors,
that may be used to justify projects. However, bypasses are less likely to impact
environmental factors directly.
Exhibit 2 lists factors identified in the theoretical literature grouped into these six
categories. The exhibit also includes three columns indicating whether the factors are
related to consumer behavior, project justification, or project impacts. Behavioral
factors generally have to do with the traffic, physical, or economic settings of bypass
projects. Project justifying factors are more likely to be cited by decision makers and
reported in project planning documents, such as Project Study Reports ( PSRs) and
Route Concept Reports ( RCRs). The behavioral and justification factors overlap
considerably.
The impact of bypasses can be varied and so are the measures that capture these
impacts. The third column in Exhibit 2 indicates some of the potential impact areas.
These often overlap with the factors that influence driver behavior. Bypass impacts are
generally captured by spatial, economic, demographic, and traffic measures.
Exhibit 2: Relevant Factors to Consider
Factors
Behavioral
Driver
Project
Justification
Project
Impact
1. Spatial Context ( Land Pattern and Bypass Design)
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Factors
Behavioral
Driver
Project
Justification
Project
Impact
Nature of Bypassed Area ( e. g., central business district,
entire community)
X X X
Nature of New Route ( i. e., urban, fringe or rural) X X
Bypass Design ( e. g., reroute highway, split business/ bypass
choice)
X X X
Highway Access ( i. e., limited access or normal access with
curb cuts)
X X X
Distance Between Proposed Bypass and Central Business
District ( CBD)
X X
Distance from Bypassed Community to Other Population
Centers
X X
Other Bypass Information ( e. g., completion year, length) X
2. Land- Use and Development Factors in Bypassed Area and
Near Bypass
Developable Land at Bypass and in Community X X
Available Infrastructure ( e. g., water, sewer, ancillary roads) X X
Proactive Zoning to Build Infrastructure ( location of bypass in
same municipality as bypassed road, bypassed municipality’s
ability to annex bypass area)
X X
Active and Stable Business Organizations ( e. g., chamber,
downtown business organization)
X X
3. Characteristics of Local Economy ( Business Mix in Pre-
Bypass Communities)
Local Community- Serving Businesses X X
Passing Traffic- Serving Businesses X X
Regional- Serving Business Center X X
Tourism or Special Attraction Location X X
Special Features ( e. g., government offices, schools) X
Stability of Local Economic Base X X
Economic Trends Before and After Bypass ( e. g., retail sales,
number of establishments)
X X X
Separation of Competing Urban Centers X
4. Traffic Characteristic ( Pre- Bypass Origin- Destination and
Trip Purpose)
Locally- Based Traffic X X X
Through Truck ( Freight) Traffic X X X
Through Passenger Traffic – Tourism and Personal Visitor
Trips
X X X
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Factors
Behavioral
Driver
Project
Justification
Project
Impact
Through Passenger Traffic – Business Trips, Service Delivery X X X
Level of Service and Extent of Congestion and Safety X X
Speed Limit on Bypass and Local Road X X
Type of Road Bypassed ( i. e., Interstate, US or State
Highway)
X X X
Adequacy of Downtown Parking X X
Other Highways Passing Through Town X
5. Demographics
Population Characteristics ( e. g., population, median age) X X
Employment ( e. g., total, employment by industry, growth in
employment, fraction in labor force)
X X
Income/ Buying Power/ Market X X
6. Environmental Factors
Air Quality X
Noise ( to the extent available) X
Caltrans planners and engineers should find the next sections particularly useful for
considering the context of California bypass projects and addressing community
groups. These sections provide case studies and evidence from academic studies that
describe the importance of the factors listed in Exhibit 2. The primary and secondary
relationships between behavioral factors and bypass impacts are discussed first.
General research findings and specific bypass examples are also cited.
1. Spatial Context ( Land Pattern and Bypass Design)
The distances between the bypass, the community it bypassed, and other population or
commercial centers are important indicators of bypass impacts. In addition to the
physical proximity, there are a number of design issues that would ease connections
between downtown and a bypass, as well as factors that might limit access.
In general, a bypass area competes with the bypassed downtown for customers and
commercial base if it is within three miles of downtown, has water and sewer, and is
more than five miles from the next nearest service exits. However, a bypass area can be
integrated with the downtown if it is less than two miles away and has supporting
water and sewer services.
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General Research Findings
• National. Assuming appropriate zoning and infrastructure are in place
or obtainable, a national study shows that travel- oriented development,
such as motels, gas stations and fast food restaurants, has a strong
negative correlation with residential development. 1
• Iowa and Minnesota. Surveys of merchants located in bypassed
communities show that merchants are more likely to oppose bypasses as
the distances between CBDs and proposed bypasses increase. 2
• Texas and North Carolina. Traffic is hard to divert from a bypass to
downtown if the bypass is part of a high- speed freeway. Lessons from
Texas and North Carolina suggest that the negative impacts of bypasses
on downtowns can be minimized by facilitate linkages through
enhanced physical access and relatively low- cost signage. 3
Specific Examples
• West Bend, WI. The US 45 bypass provides an efficient route for the
movement of goods and services. As a result, the bypass diverted
significant truck and through traffic. By reducing downtown
congestion, the bypass facilitated pedestrian access and helped promote
the downtown as a shopping area. 4
• Omak and Okanogan, WA. Locals do not agree whether the bypass of
SR- 97 in Omak and Okanogan was beneficial or detrimental. Some local
business representatives and officials point to new retail ( e. g., Wal- Mart)
along the bypass as draining the downtown economy. Others say that
the retail brings new customers to area. The downtown economy was
helped by increasing traffic on Highway 215 through town. Many
travelers take Highway 215 to reach a new mall and business sales along
the route have been increasing. 5
• Sturgeon Bay, WI. A substantial portion of the downtown business
community feels that the bypass isolates downtown from potential
1 Hartgen, David, et. al., “ Growth at Rural Interchanges: What, Where, Why,” University of North Carolina at Charlotte for the
Transportation Research Board, 1991.
2 Andersen, S. Johann, et. al.,” Economic Impact of Highway Bypasses,” Center for Transportation Research, University of
Texas, Austin. Date Unknown.
3 Wisconsin Department of Transportation, “ The Economic Impacts of Highway Bypasses on Communities,” 1998.
4 Wisconsin Department of Transportation, “ The Economic Impacts of Highway Bypasses on Communities,” 1998.
5 Gillis, William R.” Lessons from Eastern Washington: State Route Main Streets, Bypass Routes and Economic Development in
Small Towns,” Washington State University and Washington State Department of Transportation, 1994.
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traffic. In part, this is due to poor lighting and road surfaces on the
connection between the bypass and downtown that has led to
dangerous driving conditions and noise. 6
• Richmond, VA. The retention of the original route designation through
town encouraged businesses to stay after a bypass was constructed.
Inner- city tourism was stimulated by targeted signage. 7
In rural small towns, bypasses can improve access to trade centers and provide
opportunities for economic development in town
Specific Examples
• Rosalia, WA. The SR- 195 bypass reduced congestion and truck traffic in
Rosalia, which helped enhance the small- town lifestyle. The bypass also
reduced the driving time from Rosalia to Spokane, which allowed the
community to attract professionals who commute to Spokane. 8
• Rush Springs, OK. A new bypass route provided easier access to
nearby population centers and a regional Wal- Mart. While this
improved access hurt downtown businesses, it increased the job market
radius for Rush Springs residents. 9
2. Land Use and Development Factors in Bypassed Area and Near Bypass
The presence of infrastructure and planning controls on previously undeveloped land
( i. e., greenfields) often determines the pace of economic growth and the extent of
sprawl development that occurs near bypasses. Bypass routes require complementary
infrastructure ( e. g., water, sewer, and local roads) to draw business, potentially from
the bypassed downtown. Economic development around bypass interchanges will not
occur until infrastructure is planned, financed, and built, which means economic
development might not occur for decades if infrastructure is not built concurrent with
the project. However, relief from though truck traffic or excessive traffic provides the
opportunity to develop or sustaining strong residential communities in bypassed areas.
This may also support locally oriented business communities.
6 Wisconsin Department of Transportation, “ Highway Bypasses: Wisconsin Communities Share Their Experiences,” 1988.
7 Economic Development Research Group, ” Economic Impact of I- 73 Alignments on Roanoke,” 2000
8 Gillis, William R.
9 Rogers, Cynthia and Richard S. Marshment, “ Methodology for Determining the Impact of Highway Bypasses in Oklahoma,”
University of Oklahoma for the Oklahoma Department of Transportation, 2001.
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General Research Findings
• National. A national survey confirmed that downtowns can not
compete economically with developable land along bypasses. A
University of Kentucky study found that the reallocation of retail from
downtown to the bypass area stems from new retail outlets opening at
bypass, not from relocation of existing businesses. 10
• National. Infrastructure is critical for drawing businesses, particularly
fast food restaurants, to bypass areas. A package of traveler amenities
( i. e., restaurants, gas stations, and motels) is usually needed to make
new interchanges viable locations for traveler services. 11
• Wisconsin. A state study found that the cost of infrastructure at new
bypasses outweighs expected revenues from businesses. 12
Specific Examples
• Fort Wayne, IN. New bypass interchanges needed infrastructure to
make them viable as locations for economic development. In part, this
was due to the lack of residential base near the bypass to support retail.
• Danville VA. A lack of water and sewer infrastructure impeded
development along a new bypass.
Economic impacts may be determined by the ability of communities to extend political
boundaries to include the land near bypasses. This allows communities to tax or restrict
economic development. Extending boundaries is often a prerequisite for providing
adequate water, sewer and complementary roadway infrastructure near bypasses.
Specific Examples
• Sturgeon Bay, WI. The town maintained its retail and commercial
sector following the opening of a bypass because the town restricted
development along bypass corridor. According to one official
interviewed, “ you can shut down downtown” without these restrictions.
The town had jurisdiction over the bypass area as well as downtown, so
it could impose such restrictions. Local officials thought the economic
10 Buffington, Jesse L. and Womack, Katie T
11 Hartgen, et. al.
12 Collins, Margaret and Weisbrod, Glen; Wisconsin Department of Transportation, The Economic Impacts of Highway
Bypasses on Communities.
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impact might have been different had the bypass been constructed in a
municipality that competes with Sturgeon Bay for local tax revenues. 13
• Rice Lake, WI. The town annexed land and defined zoning before the
bypass was constructed. This allowed the community to raise revenues
to build complementing infrastructure. 14
3. Characteristics of Local Economy ( Business Mix in Pre- Bypass Communities)
The mix of businesses in bypassed communities is an important indicator of the positive
and negative economic effects of new bypasses. Areas that depend on pass- through
traffic are at greater risk of economic losses because they lack stable regional economic
bases, strong local customer markets, and major regional attractions and institutions.
The literature shows that bypasses reduce truck traffic and relieve downtown
congestion significantly. This provides easier driving in the downtown, improved
residential conditions and more leisurely shopping. Communities that are able to take
advantage of these changes will benefit. In some cases, bypasses seem to exacerbate
economic trends already underway and facilitate what would have been an inevitable
restructuring.
General Research Findings
• Texas. Bypassed areas lose their status as regional trading centers.
Initial declines in local business sales are offset by a reorientation of
stores from regional to local needs. 15
• Iowa. Travelers made up a lower proportion of local business in
bypassed communities than was assumed prior to construction of the
bypasses. The bypasses increased sales due to local residents taking
advantage of easier access to businesses as a result of less traffic
congestion, improved traffic safety, and easier parking. 16
Specific Examples
• Stonewall, OK. The bypass did not impact the local economy in
Stonewall, where the downtown serves a local customer base. Although
several merchants changed the orientation of their businesses, the
downtown economy did not suffer after the bypass opened. 17
13 Wisconsin Department of Transportation,” Highway Bypasses: Wisconsin Communities Share Their Experiences.”
14 Wisconsin Department of Transportation, “ Highway Bypasses: Wisconsin Communities Share Their Experiences.”
15 Andersen, S. Johann, et. al
16 Anderson, Connie and Otto, Daniel. “ The Economic Impact of Rural Highway Bypasses: Iowa and Minnesota Case Studies,”
Office of Advanced Planning, Iowa Department of Transportation, 1991.
17 Rogers, Cynthia and Marshment, Richard S.
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• Rosalia, WA. The downtown serves a local and a regional market. The
bypass created a quieter, safer environment along Main Street. This
environment helped attract new residents from Spokane, which is 30
miles away. 18
• Rice Lake, WI. The Rice Lake bypass relieved what was described as
“ extreme downtown congestion” without harming the local economy.
Rice Lake is 60 to 100 miles from other business and retail centers. 19
• Berrima, Australia. The area’s tourist economy has done well since the
removal of heavy traffic from local roads. Previously, trucking and
through traffic had detracted from the historic charm of well- preserved
colonial buildings. 20
Bypassed communities that are oriented overwhelmingly towards travel- related
services can experience very negative impacts and may require economic restructuring.
General Research Findings
• National. In an NCHRP survey of traffic- serving businesses, 49 percent
of firms reported experiencing negative impacts from bypass
construction, 30 percent reported positive impacts and 22 percent
reported no impacts. These results are consistent across small, medium,
and large communities. However, the number reporting “ no impact” is
distinctly lower in large communities than in small and medium- sized
communities. This is likely due to the larger local customer base in
these communities. 21
• Iowa and Kansas. Bypasses do not impact traveler- serving businesses
equally. Service stations, convenience stores, motels, and small cafes are
most likely to experience sales declines when new bypasses open. 22
18 Gillis, William R.
19 Wisconsin Department of Transportation, “ Highway Bypasses: Wisconsin Communities Share Their Experiences,” 1988.
20Canberra Bureau of Transport and Communications Economics, “ Economic Benefits of Investment in Transport and
Communications Infrastructure: Berrima and Mittagong Bypasses,” 1994.
21 Buffington, Jesse L. and Womack, Katie T., “ Effects of Highway Bypasses on Rural Communities and Small Urban Areas,”
National Cooperative Highway Research Program, 1995.
22 Burress, David, “ Impacts of Highway Bypasses on Kansas Towns,” Kansas Department of Transportation, 1996. and Wells,
Steve and Farnworth, Todd. “ Economic Impacts of Highway Bypasses on Small Communities – A Review” Development
Authority of the North Country, 2001.
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Specific Examples
• Rosalia, WA. A reduction in downtown traffic resulted in fewer drive-up
customers at gas stations, eating places and other highway- oriented
businesses. The downtown also lost service jobs. However, the bypass
likely exacerbated an economic decline that would have occurred
without the bypass. 23
• Mittagong, Australia. The bypass led to an overall economic decline
due to impacts on traffic- oriented businesses in town. 24
• Rush Springs, OK. Regional development moved to the highway
bypass at the expense of downtown. Three factors influenced the
decline of downtown: the new bypass, the oil- bust in Oklahoma and
two new Wal- Marts ( eight and 13 miles from Rush Springs). However,
one official stated that the “ town might have dried up anyway.” 25
• Richmond, VA. After construction of the bypass, malls opened along
the new highway and the downtown lost two major department stores.
However, the market for office space remains strong in the downtown. 26
• Fort Wayne, IN. The downtown was devastated by malls along I- 69
following construction of the bypass. The city is struggling to reinvent
itself as a corporate center for business and financial services, and as an
education and cultural center. 27
Specific destinations ( e. g., homes, employment centers, schools, government offices,
parks, churches, hospitals, cultural institutions, businesses, and stores) attract traffic
and act as buffers against negative economic impacts associated with traffic rerouting.
Bypasses tend to be beneficial for communities that contain desirable destinations by
relieving congestion and facilitating access to the destinations. This is particularly true
when bypasses enhance tourist destinations by decreasing truck traffic and moderating
congestion. Communities oriented toward tourists prior to the construction of bypasses
experience positive or no economic impact.
General Research Findings
• Wisconsin. Destinations in medium and large communities attract
traffic. In Wisconsin, all medium and large communities had more
23 Gillis, William R..
24 Canberra Bureau of Transport and Communications Economics.
25 Rogers, Cynthia and Marshment, Richard S.
26 Economic Development Research Group.
27 Economic Development Research Group.
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traffic after bypasses were built than before. The old routes are strongly
oriented towards serving locally traffic. Seventy- six ( 76) percent of
survey respondents said that they had origin or destinations within
cities. Sustained average daily traffic ( ADT) measures indicate that
traffic- dependent retailers did not need to move. 28
• Iowa. Retail businesses that serve repeat customers benefit from
improved downtown shopping environments ( e. g., reduction of truck
traffic and less overall traffic than otherwise without bypass). 29
• Washington State. A general study of bypassed communities in eastern
Washington State shows that downtowns with well- developed local
customer bases are affected less adversely by bypasses than
communities highly dependent on drive- by traffic. 30
Specific Examples
• Omak and Okanogan, WA. The two towns ( combined population of
6,500) have city limits separated by only several hundred yards. The SR-
97 Bypass of Omak and Okanogan did not result in major business
closings or empty storefronts. The towns include a long- time center for
trade and services within the region and the county seat. The towns also
have strong ties to nearby a Native American tribe. These factors
generate a significant base of retail and service industries, a mix of
highway- dependent and non- dependent businesses serving both local
and regional customers. Prior to the bypass, downtown businesses were
not heavily focused on drive- by traffic. However, businesses that were
dependent on drive- by traffic closed after the bypass opened. New
businesses that focused on the local customer base filled the vacancies
left in downtown. 31
• Richmond, VA. The growth in tourism accelerated after bypass
construction. Activities include a convention center expansion as well
as development of a canal walkway. In addition, a downtown medical
school led to the development of a biotech park. 32
• Others. Tourism benefits are seen in evaluations of bypasses for
Sturgeon Bay and Rice Lake, WI; Richmond, VA; and Berrima,
28 Wisconsin Department of Transportation, “ The Economic Impacts of Highway Bypasses on Communities,” 1998.
29 Anderson, Connie and Otto, Daniel, “ The Economic Impact of Rural Highway Bypasses: Iowa and Minnesota Case Studies,”
Office of Advanced Planning, Iowa Department of Transportation, 1991
30 Gillis, William R..
31 Gillis, William R..
32 Economic Development Research Group.
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Australia. Bypasses constructed around Sturgeon Bay and Rice Lake
relieved extreme downtown congestion during the summer tourist
season. Before the Rice Lake bypass, tourists could not cross Main Street
due to heavy traffic. 33
Declines in downtown retail may be part of general economic shifts unrelated to bypass
construction. However, bypasses can exacerbate inevitable economic restructuring
between towns and their surrounding areas. Prior economic stability is an important
indicator of how well communities fare after bypasses are in place.
General Research Findings
• National. Downtowns already affected by shopping mall development
in 1970s and 1980s probably have already restructured to office and
cultural economies. Although older, “ main street” business districts
might experience declines concurrent with bypass construction, other
causal factors may be at work, such as the attractiveness of modern
buildings and amenities that happen to locate along bypasses. 34
• Kansas. A statewide study concluded that national and regional
population/ employment trends are more important than the
construction of bypasses as a predictor of economic change. In addition,
the overall economic climate is an important consideration. Economic
downturns affect travel- related businesses regardless of bypass
construction. 35
• Wisconsin. A statewide study concluded that economic growth, which
generates traffic, is often a driving reason for building bypasses, and
that the construction of bypasses does not change these trends. 36
• Kentucky. Overall, downtowns without bypasses are healthier office
markets than downtowns that have been bypassed. A University of
Kentucky study compared downtowns with bypasses to a group of
towns without bypasses, and measured office vacancy rates of 18.4
percent in bypassed downtowns and 10.9 percent in towns without
bypasses. 37 This may be due to the development of modern office
facilities along the bypasses.
33 Wisconsin Department of Transportation, Economic Development Research Group and Bureau of Transport and
Communications Economics.
34 Buffington, Jesse L. and Womack, Katie T. and Wells, Steve and Farnworth, Todd, “ Economic Impacts of Highway Bypasses
on Small Communities – A Review,” Development Authority of the North Country, 2001.
35 Burress, David.
36 Wisconsin Department of Transportation, “ The Economic Impacts of Highway Bypasses on Communities.”
37 Thompson, Eric, et. al., “ The Impact of a New Bypass Route on the Local Economic and Quality of Life,” Kentucky
Transportation Center, University of Kentucky, 2001.
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Specific Examples
• Danville, VA. The bypass may have exacerbated a trend already
underway to restructure downtown Danville from retailing into an
office center. 38
• Appleton, WI. Downtown restructured into a cultural center with a
strong financial services sector. The curtailment in retail investment
started before the bypass was planned. Some redevelopment was
funded by public financing. However, the bypass has spawned retail
growth with negative impacts on the small towns surrounding
Appleton. 39
• Rice Lake, WI. Although Rice Lake’s commercial district thrived after
bypass construction, the town lost some retail establishments. An
evaluation of the bypass indicated that downtown merchants would
have been hurt anyway by mall construction at the edge of the city.
• Prosser and Sunnyside, WA. Each town had well- developed
downtown business districts prior to construction of the bypass. After
the bypass, the overall commercial vacancy rate for the towns stood at 5
percent. There was little impact from the bypass on these communities.
As a possible consequence of the bypass, the business mix in the
downtowns shifted from retail to professional services and government
offices. In addition, residential development increased near the
downtown, as a consequence of quieter conditions ( which may create
more retail opportunities in the future). 40
4. Traffic Characteristic ( Pre- Bypass Origin- Destination and Trip Purpose)
High average daily traffic ( ADT) and truck traffic may inhibit tourism. In these cases,
bypasses may remove trucks and excess traffic, which increases the attractiveness of
communities as tourist destinations. Relieving extreme congestion, lessening fast-moving
through traffic, and reducing the number of trucks tends to enhance local traffic
safety and ameliorate air pollution. This will also increase the attractiveness of
communities for businesses and residents. The presence of significant local traffic
suggests that merchants rely on local customers and that bypasses will have limited
impacts. The adequacy of downtown parking and access to towns after bypasses often
indicate how well communities can compete with lands made accessible by bypasses.
38 Economic Development Research Group.
39 Collins, Margaret and Weisbrod, Glen, “ Economic Impact of Freeway Bypass Routes in Medium Size Cities,” 2000.
40 Gillis, William R.
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General Research Findings
• National. The removal of heavy truck traffic from central cities led to
positive impacts by encouraging more local traffic. 41
Specific Examples
• Omak and Okanogan, WA. One reason that SR- 97 Bypass did not affect
the towns’ roles as a regional center for trade and services is that State
Route 215 still passes through town. The towns enjoyed a stable
regional commercial base, resulting in both local and regional
customers, and moderately high ADT flowing from other highways. 42
• West Bend, WI. US 45, the bypassed road, provides an efficient route
for the movement of goods and services through the city and makes the
city more accessible to cargo traffic. By relieve trucking and other
congestion, the bypass helped downtown develop a shopping area. 43
• Danville, VA. The bypass did not result in a decrease in ADT, but it
significantly reduced truck traffic. Drivers who avoided the city due to
truck traffic began driving in the city, and there were no negative
business impacts. The mall near the end of bypassed route was not
affected and is expanding. The bypass is thought to have helped the
mall by encouraging more local traffic. 44
• Richmond, VA. I- 295 has not led to reduced traffic on I- 95. The bypass
carries less than 20 percent of local traffic. Equal proportions of trucks
use the old and new routes. The old road retained the official name of
highway ( I- 95), which assisted in sustaining traffic volume. This also
encouraged businesses to remain. I- 95 was previously a toll road. Tolls
were eliminated after the bypass opened, which encouraged traffic
growth. 45
• Fort Wayne, IN. A dip in traffic followed the opening of the bypass and
a significant amount of truck traffic diverted to the bypass. Although
traffic along the old highway rebounded to pre- bypass levels, the city’s
retail sector was devastated after the bypass opened. 46
41 Buffington, Jesse L. and Womack, Katie T.
42 Gillis, William R.
43 Wisconsin Department of Transportation, “ The Economic Impacts of Highway Bypasses on Communities.”
44 Collins, Margaret and Weisbrod, Glen.
45 Collins, Margaret and Weisbrod, Glen.
46 Economic Development Research Group.
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• Berrima, Australia. The elimination of heavy vehicle traffic contributed
to the ambiance for tourists by making walking safer and easier. 47
Some bypasses provide faster or easier regional access to bypassed areas and reduce
shipment times for local businesses.
Specific Examples
• Sturgeon Bay, WI. The bypass helps businesses save on truck shipment
times by up to one- half hour. The bypass enhanced public safety as a
result of the reduction in congestion, particularly in summer. 48
• Mittagong, Australia. Traffic on the old Hume Highway declined
substantially after the bypass opened. However, the overall decline in
traffic is less than predicted due to larger stream of regional traffic
connecting through Bowrel Road. 49
• Rice Lake, WI. The bypass eliminated extreme congestion in the
downtown and the commercial district is thriving after the opening of
the bypass. 50
5. Demographics
Population is a powerful predictor of how well bypassed areas fare after the opening of
bypasses. The size of the local consumer market and the relative isolation of towns are
linked with population as indicators of how bypasses will impact the community.
General Research Findings
• National. An NCHRP study of 141 bypasses confirms that population is
an important indicator of whether communities are susceptible to
economic impacts from bypasses. Approximately half of the sample ( 71
out of 141 communities) consisted of very small towns with populations
less than 5,000. Ten of the 141 bypassed communities had negative
impacts overall, and seven of these were in small communities. 51
• Wisconsin. Over time, traffic in large and medium- sized, bypassed
communities grew to equivalent levels or greater than pre- bypass
47 Canberra Bureau of Transport and Communications Economics
48 Wisconsin Department of Transportation, “ Highway Bypasses: Wisconsin Communities Share Their Experiences.”
49Canberra Bureau of Transport and Communications Economics.
50 Wisconsin Department of Transportation, “ Highway Bypasses: Wisconsin Communities Share Their Experiences.”
51 Buffington, Jesse L. and Womack, Katie T.
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counts. Economies of very small communities ( less than 2,000 residents)
have a greater potential to be adversely affected by bypass construction.
Over time, traffic levels in communities with population greater than
2,000 are close to pre- bypass levels. 52
• Minnesota. A statewide study confirmed that the distances of bypasses
from towns and distances between towns are important indicators for
health of bypassed areas. 53
• Iowa. A statewide study suggested that communities of 2,000 or more
people and separated from competing urban centers by more than 25
miles will not suffer retail losses as a result of bypass construction.
Multiple factors are needed to predict the retail impact in communities
with populations between 500 and 2,000. Communities with
populations of less than 500 depend the most on through traffic and are
most likely to suffer economically from bypasses. 54
52 Leong, Dennis and Weisbrod, Glen, “ Summary of Highway Bypass Studies,” Minnesota Department of Transportation and
Wisconsin Department of Transportation, 1999
53 Anderson, Connie and Otto, Daniel.
54 Anderson, Connie and Otto, Daniel.
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CALIFORNIA CASE STUDIES
As part of the California Bypass Study, the project team conducted case studies of
California bypasses. This section describes the process for collecting case study data.
Caltrans planners and engineers may want to follow a similar process when considering
the economic impacts of future bypasses.
This section also presents findings from the California case studies as a series of best
practices and lessons learned. Generally, these findings mirror those found in the
academic literature. These findings should help Caltrans planners and engineers
identify policies and design features that mitigate negative economic impacts from
future California bypasses.
Towns Visited and Data Collected
Caltrans Office of Advanced Planning identified four completed bypass and ten
proposed bypasses for inclusion in the study. The project team visited local
communities for each bypass. In the case of Sonora, the project team discovered that
the Sonora Bypass was constructed prior to the recent East Sonora Bypass. While the
focus of the visit was the East Sonora Bypass rather than the Sonora Bypass, the case
study discusses some impacts of the earlier bypass. The project team also spoke with
individuals about the Roseville Bypass, which opened to traffic in 1987. While Roseville
was not visited as part of the case studies, some of the lessons learned from Roseville
are included in this handbook.
A second volume of the report provides detailed case studies of approximately 30 pages
for each bypass visited. Caltrans planners and engineers may wish to refer to these case
studies when working on similar bypasses. Exhibit 3 summarizes key attributes for the
bypasses to help planners and engineers select appropriate case studies.
Exhibit 3
California Bypasses Visited During Study
Bypass
Location
( Route and
County)
Nature of
Community
Motivation
for Bypass Illustrates
Completed Bypasses
Cloverdale Bypass
( 1995)
US 101 in
Sonoma
County
Regional
center &
residential
community
Inter-regional
traffic &
congestion
Advanced planned
and redevelopment
allowed local
economy to
recover.
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Bypass
Location
( Route and
County)
Nature of
Community
Motivation
for Bypass Illustrates
Hollister Bypass ( 1997) SR- 156 in San
Benito County
Agricultural &
residential
community
Traffic
congestion,
trucks &
safety
Bypass did not hurt
local agricultural
and bedroom
community
economy.
Mojave Bypass ( 2003) SR- 58 in
Kern County
Highway-serving
town
Inter-regional
traffic
Bypass design and
community input
are important.
Sonora Bypass ( 1987) SR- 108 in
Tuolumne
County
Regional retail
center &
institutions
Traffic
congestion
Downtown has
become a tourist
destination.
Truckee Bypass ( 2002) SR- 267 in
Nevada County
Tourist-oriented
community
Traffic
congestion
Community
concerns were
addressed in
design and
construction.
Proposed Future Bypasses
Angels Camp
Expressway
SR- 4 in
Calaveras
County
Agricultural &
residential
community
Traffic
congestion &
trucks
Bypass serves
inter- regional
traffic, while
economy focuses
on local residents.
Bishop Bypass US 395 in
Inyo County
Highway-serving
&
government
center
Traffic
congestion,
trucks &
safety
Town serves
highway traffic and
travelers have few
other options.
Brawley Bypass
( Stages 1 through 3)
SR- 78 in
Imperial
County
Agricultural
community
Inter-regional
traffic, trucks
Bypass provides
access to land for
residential and
economic
development.
Hopland Bypass US 101 in
Mendocino
County
Winemaking &
tourism
Inter-regional
traffic
Bypass may help
community turn
into a tourist
destination.
Kramer Junction
Expressway
Realignment
SR- 58 in San
Benito County
Retail service
stop
Inter-regional
traffic
Bypass may not
hurt local
businesses due to
location, design,
and services.
Lockeford/ Clements
Bypass
SR- 88 in San
Joaquin
County
Agricultural
community
Traffic
congestion
Community does
not cater to traffic
and is unlikely to
be affected.
Pine Grove SR- 88 in
Amador
County
Small town Traffic
congestion
Bypass likely to
have little
economic impact.
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Bypass
Location
( Route and
County)
Nature of
Community
Motivation
for Bypass Illustrates
East Sonora Bypass SR- 108 in
Tuolumne
County
Regional retail
center &
institutions
Ease traffic
congestion
Development can
occur along
bypass.
Sutter Creek Bypass SR- 49 in
Amador
County
Tourist
destination
Develop
pedestrian-friendly
street
Tourist- oriented
town may benefit
from bypass
construction.
Willits Bypass US 101 in
Mendocino
County.
Lumber &
regional retail
center
Inter-regional
traffic
Bypass design
may mitigate some
bypass impacts.
The Sonora and East Sonora case study is a combination of completed and proposed
bypasses and offers lessons for both. The Roseville Bypass, which is not listed in the
above table, was coupled with extensive residential and office park development and is
unlike other bypasses proposed in California. Providing access to open land was a
much a motivation for the Roseville Bypass as bypassing the existing community. The
most comparable bypass to the Roseville example is the current Brawley Bypass,
although less extensive development is currently expected.
General Findings
The case studies reiterate lessons learned from the theoretical review. In general,
bypasses impact the local economy as a function of the type of traffic addressed.
Businesses in communities with heavy local traffic or with through traffic that does not
stop will not be impacted. Communities that provide services to pass- through traffic
are more likely to be impacted. The critical issue is whether travelers had planned to
stop ahead of time or tend to make opportunistic stops. If most through travelers had
planned to stop, then the bypass design should try to maintain the convenience for
travelers to stop ( i. e., easy interchanges, bypass near businesses, etc.). If business comes
mainly from travelers that stop on a whim, the solutions for maintaining business
include finding ways to advertise to travelers ( i. e., placing bypass within sight of
businesses, providing signage on the bypass, etc.) or to move businesses near the
bypass ( providing convenient interchanges, providing inducements for businesses to
move, etc.).
The next several bullets highlight a number of issues that planners, engineers, local
business leaders, and local government should consider in planning and designing
bypasses. The findings are provided in question and answer format.
What types of towns are impacted economically?
• Highway- oriented towns ( e. g. Mojave and Kramer Junction) have a
much harder time transitioning their economies after bypasses are
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constructed than those that cater to local residents or offer tourist
attractions.
• Towns that serve as residential communities ( e. g., Cloverdale and
Hollister) or tourist destinations ( e. g., Sonora, and Truckee) can benefit
from reduced traffic and improved safety as a result of highway
bypasses. Local government and the business community may need to
engage in complementary efforts, such as marketing, downtown
redevelopment, additional parking, and sidewalk improvements, to take
advantage.
• Towns that serve regional markets by providing services, such as big
box retail, automobile dealers, department stores, or hospitals, may
experience little or no economic impacts ( e. g., Sonora). If a bypass
provides better access to regional services, the local economy may
actually improve as the town expands its regional draw.
• Towns with other economic bases, such as government employment,
mining, agriculture, manufacture, etc. are not likely to be economically
impacted by bypasses. For example, the Brawley Bypass is unlikely to
hurt the local agricultural base and may improve goods movement.
Bishop serves as a regional government center.
Which businesses are impacted?
• Gas stations and quick service or fast food restaurants cater the most to
pass- through traffic. They are most likely to be impacted by the
diversion of traffic due to bypasses.
• Other visitor- serving businesses, such as motels, art galleries, antique
stores, and curio shops, cater more to visitors attracted to the
community as a destination rather than those simply passing through.
These businesses are less likely to be negatively impacted by bypasses
and may find that business improves if the downtown is turned into a
destination.
• Regionally serving businesses, such as big box retail and departments
stores, may benefit from improved access.
• Businesses that serve local residents, such as drug stores, banks, and
grocery stores are generally not impacted by bypasses.
What other impacts occur?
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• Bypasses often have a short- term ( and negative) impact on the local
economy, but retail sales often improve in the longer term ( e. g.,
Cloverdale). However, some communities may never fully recover ( e. g.,
Mojave).
• The construction of a bypass may also provide an opportunity for
revitalization of the local community ( e. g., Brawley).
• Bypasses are often promoted as improving pedestrian safety along Main
Street. Since traffic accidents involving pedestrians are relatively rare
events, Caltrans collision statistics may not reflect improved safety.
However, bypasses may improve the perception of safety, which is a
benefit in its own right.
What design features are most important?
• Visibility. Negative economic impacts ( losses of customers and sales)
are likely to be small for businesses that remain visible from bypasses.
In some cases, the goal of making downtowns visible from bypasses
may conflict with the desire to protect communities from noise and
visual impacts. Caltrans can provide some “ visibility” for businesses
through signage.
• Distance from downtown. Bypasses located close to existing
downtowns are less likely to hurt local economies. Travelers may be
able to see businesses and access times are shorter if bypasses are
nearby.
• Direct access. Highway interchanges can provide direct access from
bypasses to downtowns and existing businesses. However,
interchanges can also encourage the development of competition to
existing businesses by offering new “ prime” locations.
• Time savings. The difference in travel time between the old route and
the new bypass determines how many vehicles ( and potential
customers) divert to the bypass.
What can Caltrans do?
• The issue of signage came up in several case studies. Local communities
offered several suggestions on how Caltrans can provide signs that may
mitigate negative economic impacts. For example:
– Caltrans could provide signs indicating services are available
at the next exit. Some businesses have offered to pay for
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signs, but Caltrans districts have raised a concern whether the
Department can be involved in “ advertising” for specific
businesses.
– Caltrans could designate the existing route as a “ scenic or
historic” route to encourage tourist traffic. However, this
must fit within the Department’s guidelines for such
designation.
– The bypass could be designated as a bypass route, while the
original route retains the State Route designation. This may
conflict with the State’s policy to avoid parallel routes.
• The large lag between initial planning and engineering and construction
may cause businesses and residents not to believe that bypasses will
eventually be built. The availability of funding and regional priorities
are beyond Caltrans’ control, but Districts should try to keep the public
actively involved, remind residents and businesses about planned
bypass, and help the community plan for the transition.
• In some case studies, businesses had made no plans to adjust their
business strategies to take advantage of planned bypasses. Caltrans can
work with local governments and chambers of commerce to encourage
businesses to plan early for bypasses. Businesses may choose to market
to local residents, change their line of business, or relocate.
• Caltrans should continue to recognize the need to conduct early
analyses of impacts on tribal governments, facilities, and economies.
Districts need to consult in the earliest planning stages and on an on-going
basis with the Native American communities as critical
stakeholders for transportation planning.
What can local communities do?
• Local communities can take advantage of reduced general and truck
traffic along Main Street by engaging in redevelopment activities, such
as main street programs, the provision of benches, planting and
improved sidewalks, economic development incentives and grants,
providing parking facilities, etc. For example, Cloverdale had a
redevelopment strategy that included these elements.
• Communities can provide roads, utilities, and other infrastructure at
interchanges along the bypass to attract businesses and encourage the
relocation of traffic- dependant businesses, such as gas stations and fast
food restaurants.
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• If a bypass remains outside of the local jurisdiction, a town can annex
territory to make sure that any economic development remains inside
the local tax base. Alternatively, the local community can zone the area
or withhold utilities and infrastructure, so developments that compete
with downtown do not occur.
• Local governments and chambers of commerce can work with local
businesses to develop business plans that take into account the change
in traffic due to bypasses. For example, the Calaveras County Chamber
of Commerce is trying to encourage Angels Camp businesses to develop
new business plans.
• The community should have a vision of how the bypass will be
integrated into the local environment ( e. g., transportation flow,
redevelopment, visual impact, economics, etc.). For example, Brawley
has a vision for the downtown. Truckee does not have a redevelopment
plan, because the town already had tourist- oriented development.
What are other issues to consider?
• A bypass is more likely to be received positively if it is proposed by the
local community than if it is motivated by inter- regional highway plans.
• Caltrans planners and engineers should recognize that the motivations
for supporting a particular bypass may differ between Caltrans and the
local community ( public and government):
– For Caltrans, the focus is on through traffic and safety issues.
Caltrans typically builds bypasses to implement infrastructure
plans ( convert conventional highway to expressway or
freeway), address mobility issues ( improve traffic flow,
improve level of service for inter- regional traffic, address
operational issues), or mitigate safety problems.
– For the local community, the focus is on local traffic and the
impacts on downtown. The local community often expects
bypasses to address problems with truck traffic ( eliminate
noise, dirt/ dust, and safety perceptions), mobility ( improve
level of serve, help local circulation, reduce idling noise in
downtown), and traffic control ( improve appearance of traffic
control measures, hold community festivals, etc.).
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• Local communities often resist accepting relinquishments until
significant improvements are made. However, the relinquishment of
Main Street to local control is an enticement in some cases.
• Traffic signals can address local circulation issues in rural communities,
but may not address long- term issues with through traffic.
• Bypasses may be unable to solve local circulation problems. Caltrans
planners and engineers need to consider whether congestion needs to be
addressed through State Highway bypasses or improvements in local
roads. For example, many rural California communities have only a
single route through town and parallel local roads may be needed ( e. g.,
Angles Camp, Bishop, and Sonora).
Later sections provide details on the retail sales, safety, and truck impacts examined in
the California case studies.
Methodology for Collecting Data
The field research conducted as part of the California Bypass Study illustrates a
methodology Caltrans planners and engineers can follow for collecting information on
bypasses. Prior to visiting the case study sites, the project team conducted in- office
research and interviewed local representatives. During the field research, the project
team conducted more interviews, examined the Main Street and bypass locations,
counted businesses, and took pictures. Exhibit 4 illustrates our approach to collection
information for the California case studies.
Exhibit 4: Approach to Case Studies
In- Office
Research
1
Contact
Key Individuals
2
Pre- Visit
Interviews
3
Summarize
Available Data
4
Visit
Community
5
Finish Case
Study
6
Step 1. The project team reviewed published reports. Important reports to consider
include: Project Study Reports, environmental reviews, Route Concept Reports, and
other project summaries developed for inter- regional planning. These reports provide
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historical background, project justifications, and some information about the local
community. The team collected traffic data and Traffic Accident and Surveillance
Analysis System ( TASAS) collision data from the Division of Traffic Operations as well
as economic and demographic data from the Department of Finance ( DOF) and the US
Census Bureau. Critical economic data include employment and number of
establishments from the Census Bureau’s ZIP Code Business Patterns. DOF provided
population trends and current demographics. The team also reviewed newspaper
articles from online searches and public hearing notes as available.
Step 2. The project team contacted Caltrans staff knowledgeable about the bypasses.
This was typically the project engineer, but sometimes the person with the most project
history no longer worked in the District. The team explained the purpose of the study -
documenting the economic impacts of California bypasses and identifying best
practices and lessons learned. District representatives were asked to provide a history
of local transportation issues and the bypass. They were also asked to help identify key
stakeholders to interview during the site visits, such as city representatives, county
representatives, chambers of commerce, local business leaders, and Native American
representatives. The bypass project managers also explained the motivating factors for
constructing the bypasses, potential traffic and safety impacts, and community
objections. The critical lesson is to review all data available at Caltrans before
contacting local representatives.
Step 3. As part of the pre- visit data collection, the project team called a number of local
representatives:
• City planning department staff
• City public works and traffic engineers
• County representatives
• Chambers of commerce and the business community
• Native American and tribal representatives
• Economic development commissions
• City managers
• Regional Transportation Planning Agencies ( RTPA)
• Finance directors.
The lesson for Caltrans planners and engineers is the importance of talking to
community groups or neighborhood associations. Exhibit 5 provides a sample of the
guide used in the interviews. Planners and engineers should ask similar questions
when talking to local groups.
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Exhibit 5: Questions Asked During Bypass Interviews
􀁨 Nature of community ( size, special features)
– Future plans ( attract more tourists, stay same size)
– Economic and traffic information ( what drives economy, how economic base has changed, local traffic data)
􀁨 Nature of bypass
– Reason for bypass
– Community perspectives about bypass ( local leader opinions, objections raised, perspectives after completion)
– Other factors ( infrastructure available, development plans, political issues)
􀁨 Impacts ( traffic, safety, local business, general economy, downtown, environment, development along bypass)
– For proposed bypasses, possible impacts and community concerns
– For completed bypasses, what happened?
􀁨 Wrap- Up
– Do you have documents we should review? ( mail or we will pickup)
– Mention field visit and set a time to meet
– Who else do you suggest contacting?
The project team also tried to collect published documents and data prior to visiting the
bypass sites, including:
• General plans
• Economic studies ( economic development and cluster analyses)
• Traffic studies ( counts, forecasted impacts, and origin- destination
surveys)
• Consultant studies ( e. g., sponsored by local chambers of commerce)
• Tax receipts or other data that substantiates business impacts.
Step 4. Before visiting each site, the project team prepared rough situation summaries to
identify gaps and data to be verified during the field visits. The team also identified the
location of businesses likely impacted by shifts in pass- through traffic ( e. g., gas stations,
restaurants, motels and hotels) using information from market research firms. Several
firms provide comparable market information, including InfoUSA and Dunn and
Bradstreet.
Step 5. During each field visit, the project team conducted windshield surveys of the
downtown and, in the cases of completed bypasses, the bypass site. The team walked
the bypassed corridor and verified the market research information on the locations of
business establishments. In some cases, businesses had moved or turned over. The
project team also met with the representatives contacted earlier. Other activities
included: examining available parking, observing traffic in the downtown, talking with
local residents, and taking pictures. The lesson learned for Caltrans planners and
engineers is the need to verify businesses along the bypassed corridor rather than
relying on published sources.
Step 6. After returning from the field visits, the project team compiled available
information to identify the overall impacts of the bypasses, strategies ( e. g., designs,
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complimentary policies, etc.) that led to successful outcomes and lessons that could be
learned for future California bypasses.
The case studies provide an example of how detailed economic analyses can be written.
They show that local communities are most frequently concerned about the potential
loss of businesses and accompanying jobs. They also show how economic impacts can
be estimated. The following factors are critical for estimating the economic impacts of
bypasses on bypassed communities:
• Extent of specific types of businesses bypassed ( visitor and pass- through
traveler serving businesses, commercial establishments, local- serving
commerce, regional- serving commerce, industry, and office)
• Lost traffic
• Extent to which trip purposes ( as collected in travel surveys) suggest
that traffic will leave rather than continue to use local businesses
• Potential for development in areas made accessible by bypasses.
The HBI Model, described later in this report, helps estimate the range of gains, losses,
or shifts in jobs associated with highway bypasses given the nature of the bypasses,
relevant traffic, and local settings. The case studies also point to quality of life impacts
that can be evaluated as direct consequences of road design, such as delay
improvements, reduced delays, elimination of traffic backups, and fewer trucks on
residential streets. However, other quality of life improvements, such as sprawl, infill
development, truck noise, air quality and perceptions of pedestrian safety can evaluated
in qualitative terms only after discussions with local experts, community groups, and
business associations about zoning, available infrastructure, and development plans.
Retail Sales
The project team looked at retail sales for four completed bypasses ( i. e., Cloverdale,
Hollister, Roseville, and Truckee) to see if impacts or trends could be identified. The
team was unable to consider the impacts in Mojave because the community is
unincorporated and the bypasses opened to traffic too recently for published data to be
available. However, anecdotal evidence suggests that the bypass had negative impacts
on local businesses. Sonora was also excluded from the analysis because the bypass
opened nearly two decades ago and the case study had focused on the recent East
Sonora Bypass.
The team conducted an “ in- office” analysis by examining retail sales for each town as a
whole. Due to limits in the data available from published sources, we could not
consider whether the bypasses shifted business from the downtowns or the existing
routes to new locations within the towns. The project team also did consider whether
business ownership is local or national, which is often a factor for local stakeholders.
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Data Available
The project team was able to collect taxable sales information for three industries of
interest:
• Eating and drinking places
• Service stations
• Food stores.
The project team chose the first two because they are likely to serve pass- through traffic
in addition to local residents. Food stores were added because they may have trends
similar to eating and drinking places, but are more likely to serve local residents than
pass- through traffic. Due to data reporting limitations, the project team could not get
industry- specific data for Roseville and had to settle on sales for an “ all retail” industry.
Data were not available for Mojave because it is unincorporated.
The project team also wanted to get information on accommodations ( i. e., hotels and
motels), since they are likely to serve pass- through traffic. However, accommodations
are not subject to sales tax and transient occupancy taxes for accommodations are levied
at the local level. The team tried to collect transient occupancy tax information from
local and county governments during the site visits, but this information was not
universally available.
The project team consulted a number of sources to collect retail sales and other
information for the analysis:
• Retail sales figures from the California Board of Equalization ( BOE)
• On- line reports, 1999 to 2004 ( see www. boe. ca. gov/ news/
tsalescont. htm)
• Published data, pre- 1999 from the MTC Transportation Library
• National GDP deflator statistics from the Fiscal Year 2005 Budget of the
United States Government: Historical Tables, Table 10.1 ( see
www. gpoaccess. gov/ usbudget/ fy05/ sheets/ hist10z1. xls
• Population estimates from the California Department of Finance ( DOF),
see www. dof. ca. gov/ HTML/ DEMOGRAP/ repndat. htm.
Data Analysis and Findings
The project team converted nominal retail sales into real retail sales ( in Year 2000
dollars) using the GDP deflator. For each bypass, the project team graphed real retail
sales over a ten- year period that spans five years before and five years after the bypass
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opened. We noticed that retail sales rose over time for many of the bypasses and
realized that much of this growth might be due to population increases.
The project team divided retail sales by DOF population figures, but found that the per
capita sales graphs showed trends similar to general economic booms and busts. The
overall economy improved from 1995 to 2001, and so did retail sales. The per capita
sales figures could reflect industry- specific factors ( such as gasoline cost increases for
service stations) that are unrelated to construction of the bypasses. To adjust for general
economic and industry- specific trends, project team decided to divide local per capita
sales by comparable statewide per capita sales. The project team calculated ratios for
each industry and bypass. The resulting ratios show changes that occur regardless of
inflation, population growth or underlying economic trends.
Exhibit 6 summarizes the impacts for the four bypasses examined. As the exhibit
shows, the impacts of the bypasses on retails sales were mix. Sales improved in some
cases, while they declined in others.
Exhibit 6: Summary of Impacts
Pass- Primarily Local- Through Serving Industries
Serving Industry
Roseville - - or = +
Cloverdale “ All retail” +
Truckee - - -
Hollister + = =
Eating and Drinking Service Stations
Bypass Food Stores Places
Key: - Declining Retail Sales = Steady Retail Sales + Increasing Retail Sales
Although our initial intent in calculating local- to- state sales ratios was to compare sales
before and after bypass openings, the project team noticed that the ratios reflect
fundamental differences in the economies of the bypass areas. For example, the sales
ratios for service stations and eating and drinking places in Hollister tend to range in a
from 0.6 to 0.8, while comparable figures for Truckee exceed 1.4 and range as high as
2.7. Per capita sales in Hollister tend to be less than statewide averages, while sales in
Truckee far exceed these averages. This result makes sense, since Truckee is near
several ski resorts and may serve destination ( non- local) traffic. The project team tried
calculating local- to- county ratios, but the trends are similar to those for local- to- state
ratios.
This suggests that Caltrans could interpret the sales ratios in a manner similar to the
concept of location quotients used in regional economic analysis. Location quotients
California Bypass Study
Final Report Volume 1 - 46 - System Metrics Group
measure the strength of a region’s economic activity relative to a control area, such as
the state. A quotient of less than 1.0 suggests a region is underserved and is a net
importer for a particular industry, while a figure above 1.0 suggests that a region is
overserved and is a net exporter. Applying the same logic, a region that has a local- to-state
ratio for service station sales that far exceeds 1.0 is more likely to serve pass-through
and destination traffic.
In developing the HBI Model, the project team saw similar results for case studies
nationally. 55 Exhibit 7 shows how sales changed after bypasses were constructed in
relation to the number of services stations per capita. Communities that had relatively
more services stations per capita were more likely to be hurt economically after the
bypasses opened. This reinforces the idea that communities with many service stations
( and high gas station sales) are net exporters of gas station services. That is, they tend
to be highway oriented and hurt economically by bypasses.
Exhibit 7: Impact of Bypasses on Retail Sales as Compared to the
Number of Gas Stations in Communities
West Bend , WI
Spooner , WI
Mt. Horeb , WI
Holmen , WI
Truckee , CA
Sonora , CA
Hollister , CA
Cloverdale , CA
Wharton , TX
Vernon , TX
Smithville , TX
Sinton , TX
Silsbee , TX
Raymondville , TX
Ranger , TX
Plainview , TX
Pearsall , TX
Navasota , TX
Marlin , TX
Livingston , TX
Littlefield , TX
La Grange , TX
Henrietta , TX
Gatesville , TX
Fort Stockton , TX
Electra , TX
El Campo , TX
Edna , TX
Coleman , TX
Cleveland , TX
Bowie , TX
Sunnyside , WA
Prosser , WA
Omak , WA
0.00
0.50
1.00
1.50
2.00
2.50
0.00 0.50 1.00 1.50 2.00 2.50 3.00
Number of Gas Stations per 1,000 Population
Retail Sales Index ( Before = 1.00)
Source: HDR analysis of retail sales data
The differences in the number of gas stations and sales across communities could also
be due to regional consumption patterns ( e. g., differences in average trip lengths and
automobile usage for service stations, differences in the proclivity to eat out for
restaurants, etc.). However, a high local- to- state sales ratio in pass- through serving
industries may be a “ red flag” indicating a community where Caltrans should pay
particular attention to the potential impacts of a bypass, consider design alternatives
55 The national bypass case study database is described further in the documentation for the HBI Model that was developed as
part of this study.
California Bypass Study
Final Report Volume 1 - 47 - System Metrics Group
( such as interchange locations and signage), and mitigation strategies ( such as
facilitating downtown redevelopment).
Safety Impacts
The project team compiled a database of collision information for all completed and
proposed future bypasses in the study. The database includes information from TASAS
and from the California Highway Patrol Statewide Integrated Traffic Records System
( SWITRS). The team also collected information from local agencies and Project Study
Reports.
A review of project reports for previously constructed bypasses revealed that they are
often justified on the basis of reducing highway collisions by easing conflicts between
local and through traffic, particularly in downtown areas. For example, the Roseville
Bypass project report sets a goal of reducing “ side friction” from street intersections
( Roseville Bypass Project Report, June 11, 1963). Study documents for the Mojave
Bypass describe the need for “ reducing congestion, driver impatience, speed
restrictions, turning conflicts between business traffic with through traffic” ( Mojave
Bypass Supplemental Project Study Report, April 1992). Caltrans documents for other
projects discuss the need to minimize sideswipes, rear- ends, and other collisions related
to interactions between through and local traffic. Future bypasses are also proposed to
lessen highway collisions.
Given the interest in the safety impacts of bypasses, it is useful to consider what
happened in the case of some already- built bypasses in California. This section
summarizes what happened for three bypasses – Cloverdale, Hollister, and Truckee.
Although the project team did not find conclusive evidence that the bypasses improved
safety, we also did not find evidence that they diminished safety.
Data Available
The safety database includes a combination of information from TASAS and SWITRS.
Originally, the project team collected information from TASAS only, but quickly found
that the electronic files have data for only ten years ( 1994 to 2003). Caltrans publishes
an annual summary of TASAS information and these reports are available at the
Caltrans library in Headquarters. The most detailed information in the published
reports is at the county and district levels only, which is not sufficient for this analysis.
The project team decided to examine the CHP SWITRS database, since this is the origin
of the TASAS data. SWITRS differs from TASAS in only two respects: 1) SWITRS
contains information for all California roads ( not just State Highways), and 2) Caltrans
adds highway geometric information to the TASAS database that is not available in
SWITRS.
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While CHP carefully controls access to SWITRS, they publish annual reports, which are
available in the Caltrans library. The published SWITRS reports provide more detail
than the TASAS reports do. From the SWITRS reports, the project team was able to get
information at city and county levels. Although SWITRS data are available for a
number of years, the project team chose to collect data for ten years:
• For previously built bypasses, five years before construction and five
years after construction
• For future proposed bypasses, the last ten years.
Analysis and Findings
In order to consider the safety impacts of bypasses, the project team could examine only
bypasses with sufficient before and after data. The Roseville and Sonora bypasses,
which opened to traffic in 1987, are too old for before data to be available from TASAS.
Thus, the California Bypass Study includes only four previously constructed bypasses
with available data:
• Cloverdale ( opened in 1995)
• Hollister ( opened in 1997)
• Mojave ( opened in 2003)
• Truckee ( opened in 2002).
Mojave and Truckee opened very recently, so we do not have sufficient after data to
conduct an impact analysis for these bypasses. The Roseville and Sonora facilities have
been open for more than a decade. Although this provides us with sufficient after data,
the project team was unable to collect before data from TASAS. Using SWITRS data,
the team could look at how the number of collisions changed at the city- level, but it
would be difficult to control for the rapid growth of the community and traffic. We also
considered adding information from Roseville and Sonora project reports, but it was
difficult to make comparisons between this information and the TASAS data. As a
result, the project team decided to focus on the Cloverdale and Hollister bypasses. A
brief description of the short- term safety impacts in Truckee is included at the end of
this section.
The team began by examining the total number of collisions. As shown in Exhibits 8
and 9, we found an unexpected phenomenon. For both bypasses, the number of
collisions increased on the routes that were bypassed after an initial, marginal decline.
After about four or five years, the number of collisions fell to or below pre- existing
levels. One theory is that that new traffic patterns lead to driver confusion and more
collisions. Once drivers sorted out the new route, safety benefits were finally realized.
However, it seems unlikely that this adjustment period would require four to five years.
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Exhibit 8: Cloverdale Bypass - Total Collisions
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
1994 1995 1996 1997 1998 1999 2000 2001 2002
Year
Total Number of Accidents
Bypass Opened
Cloverdale Blvd
( Bypassed Route)
Rte 101
( Bypass)
Exhibit 9: Hollister Bypass - Total Collisions
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003
Year
Total Number of Accidents
Bypass Opened
Old Rte 156
( Bypassed Route)
Rte 156
( Bypass)
The project team decided to examine fatality and injury collisions alone. As shown in
Exhibits 10 and 11, we got mixed results. For the Cloverdale bypass, the pattern for
fatality and injury collisions was similar to that of collisions overall, just less
pronounced. However, for the Hollister bypass, the number of fatality and injury
collisions remained steady and then declined after four to five years. This suggests that
the bypasses reduced the incidence of more severe collisions and increased the
proportion of property damage only ( PDO) collisions. Perhaps, the bypasses removed
through drivers who were less familiar with the local roads and more likely to cause
severe collisions, while local drivers began to drive more aggressively in the presence of
less traffic and cause more minor collisions.
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Exhibit 10: Cloverdale Bypass – Fatality and Injury Collisions
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003
Year
Total Number of Injuries + Fatalities
Bypass Opened
Cloverdale Blvd
( Bypassed Route)
Rte 101
( Bypass)
Exhibit 11: Hollister Bypass – Fatality and Injury Collisions
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003
Year
Total Number of Injuries + Fatalities
Bypass Opened
Old Rte 156
( Bypassed Route)
Rte 156
( Bypass)
The two bypasses were constructed at about the same time, so another possibility is that
the increase in collisions is due to general economic and traffic conditions rather than
the opening of bypasses. The project team tested this theory by examining collision
rates, which control for traffic levels. As shown in Exhibits 12 and 13, the patterns for
the collision rates were similar, although somewhat muted, to those for the number of
collisions.
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Exhibit 12: Cloverdale Bypass - Total Collision Rate
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003
Year
Accident Rate ( per Million Vehicle Miles)
Bypass Opened
Cloverdale Blvd
( Bypassed Route)
Rte 101
( Bypass)
Exhibit 13: Hollister Bypass - Total Collision Rate
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003
Year
Accident Rate ( per Million Vehicle Miles)
Bypass Opened
The collision rates for the new bypasses show similar rise and fall patterns, so the
change in collision rates may be due to other factors:
• Small towns – The number of collisions in small communities is
typically fairly small. For example, Cloverdale Boulevard had only 13
collisions in 1994. Since this is a small base, a single collision can change
the collision rate drastically.
• Traffic volumes – Caltrans validates the traffic volumes used to derive
collision rates only once every three years. Traffic volumes are
estimated for intervening years. There may also be only one count
station in a given community. Relatively low collision rates could be
influenced strongly by the frequency and location of traffic data
collection.
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• Causal factors – While the TASAS database includes information on
causal factors, such as drugs, alcohol and speeding, the number of
collisions was too small to control for these factors. A few collisions due
to factors other that a bypass opening ( such as drunk driving) could lead
to higher collision rates despite the construction of a bypass.
• Collision type – New bypasses may help reduce certain types of
collisions, while not impacting the frequency of other collisions. For
example, as cited in some of the project study reports, bypasses may
reduce side collisions at key intersections or near downtown parking
areas, but may not reduce rear- end collisions at stoplights. The project
team was unable to consider the effect of collision type, again due to the
small number of collisions near the two bypasses.
• Operational changes – Communities may also influence collision rates
by changing downtowns in ways that alter highway operations. For
instance, a reduction in truck traffic in the downtown area due to a
bypass may encourage a community to introduce a new parking
scheme. While this scheme may be intended to enhance downtown
business, it may also impact collision rates.
TASAS data are available for only one year ( 2003) after the Truckee bypass opened.
However, it shows a substantial improvement in local traffic safety. As shown in
Exhibit 14, the number of collisions along SR- 267 in Truckee ranged between 2.02 and
2.61 collisions per million vehicle- miles ( MVM) in the decade before the bypass was
built. Immediately after the bypass opened, the collision rate along the old route
dropped from 2.34 collisions per MVM in 2002 to only 0.53 collisions per MVM in 2003
due to the diversion of traffic. Note that the drop started to occur in 2002, reflecting the
two months the bypass was open that year. The collision rate along the new bypass
route was 1.05 per MVM in 2003. While higher than the rate along the former route
during the same time period ( due to traffic volumes and out- of- town drivers), it was
significantly lower than the rates along SR- 267 during the previous year. The average
rate across both facilities shows that the construction of the bypass helped reduce
collisions in the area.
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Exhibit 14: Collisions per Million Vehicle Miles in Downtown Truckee
-
0.50
1.00
1.50
2.00
2.50
3.00
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Year
Accident Rate
Bypassed Route
Bypass
Source: Caltrans Traffic Collision Surveillance and Analysis System
On the basis of this very limited data, the project team is unable to draw concrete
conclusions about the safety impacts of bypasses. However, they are most likely to
improve traffic safety or keep collision rates unchanged. Interviews conducted during
the field visits indicate that there are often perceived safety issues for pedestrians when
high volumes of through traffic occur in downtown areas. By removing this traffic,
bypasses have the potential to improve the perception of safety, which may be as
important to the public as measurable improvements in traffic safety.
Truck Traffic
Although truck traffic is likely to affect individual communities differently, the quality
of life issues associated with trucks ( noise, dust, idling, safety, and air quality) are a
function of the percentage of trucks in town. The project team examined truck traffic in
California small towns using a combination of traffic and truck counts from the
Caltrans Division of Traffic Operations and population data from the Department of
Finance. By combining these data with GIS land- use data, the project team was able to
compare traffic volumes in town with those leaving and entering town.
Exhibit 15 shows the truck shares of traffic counts for pass- through traffic and for local
traffic. The differences in traffic volumes outside town limits with those inside are
assumed to be through traffic. As the exhibit indicates, trucks m