Center Identification Number: 576-10
Project Title: Impacts of Transit Oriented Development on Public Transportation Ridership– Phase One
Sara J. Hendricks
for Urban Transportation Research (CUTR)
External Project Contact:
Amy Datz, Transit Program Manager
I. Project Objective
The purpose of this study is to address the question of the effectiveness of transit oriented development (TOD) when combined with good quality transit service, to shift the mode share of commuters from single occupancy vehicle (SOV) travel to transit use.
II. Project Abstract
This project would constitute a Phase I exploratory stage of a study to address questions regarding the effectiveness of combining appropriate land use, development densities and urban design with good quality transit to shift SOV travel to transit travel. Several recent research sources have appeared to indicate that TOD is not delivering on promises to shift travelers to transit in addition to research conclusions that no matter how good quality the transit service, commuters will not give up their cars. Recent research suggests that even if good quality TOD is combined with good quality transit service, these two elements must also be combined with strong disincentives not to drive in order to achieve any appreciable shift in mode share from SOV to transit. This study will attempt to address this question, first by a closer examination of the many variables not considered, which define quality TOD as well as developing a working definition for “good quality transit.” Phase I will identify established TODs and evaluate them against standards of performance when combined with transit service of varying degrees of service quality. Through a more detailed literature review, particularly of studies of existing TODs, Phase I will also detangle the many questions that have arisen from previous research studies in order to more closely specify a research question. From this foundation, a research design will be developed for Phase II.
III. Task Descriptions
Task 1: A detailed literature review will be conducted regarding the effectiveness of TOD by looking more closely at the features of these TODs as well as the varying contexts within which they operate. A detailed examination of transit services that are combined with established TODs will also be done to determine level of quality and identify those systems that could be used as examples of “good quality transit.”
Task 2: While this may change as a result of the literature review, it is initially proposed that the information for a comparative study be collected for the later examination of the various combinations below. For purposes of study simplicity, it is proposed that one trip type be selected: looking at travel mode choice for commute trips to the urban core resulting from the following combinations at a suburban trip origin.
Study Scenarios of TOD With Various Combinations of Other Influencing Factors
The table above describes eight possible scenarios of good transit combined with various combinations of other influencing factors, which include good quality TOD, disincentives to private auto use, TOD that serves low-income commuters, and TOD that serves commuters who are not low income. The “X” indicates the presence of that factor. For example, Scenario #1 describes the case in which good quality transit is combined with TOD that is not considered good quality (or no TOD at all), no disincentives to private auto use, and that serves low-income commuters. This study would develop a method to research how to evaluate the impact of this combination of circumstances upon transit ridership.
Task 3: A memorandum will be prepared to interpret the findings of the literature review and the data on TOD and supporting transit services. A research question will be defined and a research design will be developed, through an appraisal of alternative types of quantitative analysis. Recommendations will be given with regard to the most appropriate and instructive analytical approach.
IV. Student Involvement
Graduate students will assist in the research and data collection as well as the analysis. Other anticipated student benefits will include synthesis of information and technology transfer support.
V. Relationship to Other Research Projects
Studies by Reid Ewing and Ruth Steiner found no reduction in travel demand as a result of TOD. Quality of transit was not considered. While the quality of TOD studied is also not known, Dean Belzer and Gerald Autler (2002) concluded that most development labeled as TOD fails to have the qualities necessary for TOD to function successfully. This conclusion is supported by a recent Florida State University (FSU) study that examined examples of TOD in Florida.
Ewing and Robert Cervero conducted a literature review and synthesis (2001) of more than 50 recent empirical studies on how the built environment affects travel demand. They found transit mode choice among the components most extensively studied and that transit use appears to be more prevalent in traditional urban settings, although it is not known whether people who prefer transit choose neighborhoods that support transit (self-selecting), or whether such neighborhoods cause motorists to take transit. The studies reviewed support the hypothesis that transit trips in traditional urban settings substitute for auto trips rather than supplement them. They also found evidence that traditional neighborhoods support greater shares of transit for non-work trips than for conventional neighborhoods. They reviewed 35 recent studies that tested the impact of various land use characteristics on travel and found that of the three travel variables (trip frequency, trip length, mode choice), mode choice was most affected by local land use patterns and that transit use primarily depends on local densities and secondarily, on the degree of land use mixing. They also found that mode share depended both on urban design and socioeconomic factors. Ewing and Cervero also computed travel demand elasticities to account for the effects of higher densities, mixed land uses and pedestrian-friendly designs on vehicle miles traveled (VMT) and vehicle trips. EPA’s Smart Growth Index model used these values. They found that while the typical elasticity values for each variable are not large in absolute terms, these values are significantly different from zero in most cases and when summed across the factors of regional accessibility, density, land use mix and design, they suggest fairly large cumulative effects on travel demand. This may suggest that good transit (that providing regional accessibility) combined with TOD (which incorporates density, land use mix and urban design) may prove to have a cumulative effect on travel demand, including mode choice.
The hypothesis is suggested that while it may be true that TOD by itself will not replace SOV travel with transit trips, good TOD combined with good quality transit service will. What seems to emerge from the literature on the subject is that achieving significant gains in mode share by transit requires many more than two ingredients (good TOD plus good transit); it requires the cumulative sum of a variety of circumstances together.
In TCRP Report 27, Building Transit Ridership, An Exploration of Transit’s Market Share and the Public Policies That Influence It, it was concluded that current case studies demonstrate that large improvements in transit market share requires both incentives to ride transit, as well as disincentives to use private automobiles. Strategies that focused solely on improving the level or quality of transit service were generally unsuccessful at achieving a marked mode shift to transit. Case studies showing clear transit ridership gains also had circumstances that were particularly unfavorable to private vehicle use, specifically parking unavailability and high parking prices. The study also concluded that:
The auto ownership decision dominates the mode choice hierarchy. Because the decision to own (or lease) a vehicle is so central to the entire choice process, and because this process is ultimately driven by lifestyle choices that are increasingly making the private vehicle ownership decision a “given” for many people, automobile users need more than an incentive to use transit. Put simply, they need a strong incentive not to drive.
The circumstances under which transit can offer comparable advantages include dense travel corridors, congested highways with travel time advantages for transit, low private vehicle ownership levels, and high private vehicle usage costs. The study recommended that additional research be mostly on strategies that influence directly the attributes of private vehicle travel, such as limitation of urban freeway capacity and congestion-sensitive road pricing, both of which are very difficult to implement politically.
For this proposed study, we can attempt to find “good” TOD based upon the development of a definition of TOD, as supported by the findings of Belzer and Autler. The definition would include pedestrians being able to satisfy most routine personal trips within a 5-10 minute walk (one quarter mile). It would also include attributes that address the issue of auto ownership, enabling or requiring TOD residents to limit auto ownership (such as location efficient mortgages, a car sharing agency located within the TOD) and encouraging commuters to the TOD to arrive by transit through parking unavailability or high parking pricing.
While parking unavailability is almost always politically difficult, it is more easily achieved in dense downtowns, where commercial space replaces parking. However, as work locations continue to move to the suburbs, space to provide parking on suburban parcels is abundant. Some research suggests that automobile restraining policies, such as parking unavailability, actually move businesses out of center city and contribute to sprawling development patterns that are difficult for transit to serve (TRB paper, Shiftan, 2003).
The more successful TODs, such as the Village at Overlake Station in Redmond, WA, combine TOD, quality transit service and affordable housing, putting to use those households who cannot afford cars. In this case the key disincentive to drive private automobiles is the cost of private car ownership and maintenance to the residents, which is generally not a deciding factor in the personal transportation decisions of middle-income and affluent individuals.
Because low-income persons ride transit more than middle and upper income persons, it is considered necessary to control for income to gauge the true effectiveness of TOD to replace SOV trips with transit trips. Many TODs include affordable housing, so the thought is to exclude TODs with affordable housing from the study. However, many TODs include affordable housing to create an instant market for the transit service as well as to secure affordable housing loans. An alternative is to segment the study into two sections, initially examining only TODs that include affordable housing and comparing mode share with other affordable housing communities. Even though low-income persons are less likely to own automobiles than middle and upper income persons, they still own some cars, and these cars take a bigger percentage of total personal income. Low-income persons have the most to gain financially by being able to get rid of their cars and so it would seem that this would be an effective incentive not to drive. Good TOD and good transit may offer a solution.
Can low-income persons be more easily persuaded to not buy cars or to dispense with their cars? Is targeting low-income persons effective in eliminating peak period SOV travel? Is it a good solution? In TRB Transportation Research Circular E-C026, Understanding Automobile Ownership Behavior of Low-Income Households, it is concluded that while non-poor households exhibit a bias toward higher automobile ownership, poor households convert income to automobiles at twice the rate of non-poor households. However, the study found that poor households respond to transit availability to the same degree that non-poor households do. What this seems to suggest, as concluded by the TRB study, is that in our society, in order to fully engage in the range of employment and other opportunities, all households need cars and that transportation planners and policymakers should seriously consider and pursue non-transit solutions to address the mobility issues of the poor. The variables defining transit service in the study were three, including access to any form of transit, access to rail, and distance to the nearest transit stop. It would seem that these defining variables use overly broad-brush strokes. Conditions surrounding these three transit-related variables could range widely from “good” transit service to very poor transit service.
That poor households respond to transit availability to the same degree that non-poor households do may simply be an indication that poor people will not ride ineffective transit service as much as affluent people. While the TRB study shows that poor households convert income to car purchases at twice the rate as middle-income households, one would expect that poor households would use available transit service to a greater degree to save money. However, the TRB study shows that poor households with automobiles do not ride available transit any more so than middle-income households, and as a result, the study concludes that transportation policy should support the choice of poor households to drive cars by pursuing non-transit solutions for mobility. This proposal challenges that conclusion by questioning what is meant by transit availability. If a bus passes by a street only twice daily, it may be considered an available service, but certainly not an effective service that meets the transportation needs of many in the community. If the transit service is ineffective, then poor households will not waste their time riding transit either, no matter that it is a less expensive option than owning an automobile.
From the variety of conclusions presented in this brief literature review, it is suggested that it may be worthwhile to challenge the notion that TOD does not replace SOV trips with transit trips.
VI. Technology Transfer Activities/Peer Review
The memorandum resulting from Phase I will be available on the NCTR website (www.nctr.usf.edu) in HTML and pdf formats. The results of this project will be made available at conferences in Florida such as Florida Public Transportation Association, American Public Transportation Association (APTA), Transportation Research Board (TRB) and other related venues. A brief presentation by the PI will be recorded and available for playback as a streaming media presentation on the NCTR website.
Invited representatives to serve as peer reviewers will include representatives from the Florida Department of Transportation, the Federal Transit Administration and the TRB Committee on Transportation and Land Development.
VII. Potential Benefits of the Project
The results of this study are intended to help us better understand what combinations of circumstances are needed to effect a change in mode share toward greater use of transit, as well as develop and incorporate increased knowledge of how quality of service affects travel behavior.
VIII. TRB Keywords:
transit oriented development, transit
1. Time Line
Notes: This budget does not reflect any federal participation.
The project team will include faculty, students, and secretarial and other support staff who will work directly on the project and whose costs are reflected in the direct costs of the project as listed above.
*Expendable Property/Supplies includes printing, copying, postage, telephone, office supplies used by this project, and other miscellaneous expenses.
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