Center Identification Number: 77716
Project Title: Integrating Transit and Urban Form
Sisinnio Concas, Senior Research Associate
Center for Urban Transportation Research
University of South Florida
External Project Contact:
Public Transportation Office / Transit Planning
I. Project Objective/Problem Statement
Despite a significant amount of academic and practitioner-oriented research, the practice of choosing the right transit service to support desired development and the right development to support transit ridership is still constrained by a lack of information and data.
The objective of this task is to develop an integrated approach to examining the relationships between transit design and urban form indicating the relationship between transit and land-use variables. This research also will synthesize academic research and practitioner-based work examining the relationships between transit design and urban land use. This study will complement academic research and practioner-based work by providing a formal and integrated approach to examining relationships between transit design and urban form, resulting in clearly-defined variables for transit and land-use.
The approach, compared to empirical studies currently available, will provide a formal framework to control for feedback effects between transit mode and urban form, while taking into account substitution and complementary effects, as explained in Task 2.
Despite a significant amount of academic and practitioner-oriented research, the practice of choosing the right transit service to support desired development and the right development to support transit ridership is still constrained by a lack of information and data. At the regional scale, spatial allocation of job centers has changed in the past 30 years, diminishing the primacy of the central city and increasing suburb-to-suburb trips. This has had a profound impact on the way transit responds to urban form, yet there is little information to guide local and regional decision-makers.
Early studies, such as the work done by Jeffrey Zupan, empirically established the housing and job densities necessary to support different transit modes. While these research efforts continue to be a primary reference for identifying the densities and urban design necessary to support viable transit service, they do not consider the emergence of new mixed-use, transit-oriented developments that have emerged in the marketplace. Little analysis has been done concerning which of these new types of development are most appropriate for which contexts—urban versus suburban downtowns, neighborhoods versus commuter town centers—each of which is likely to need a different kind of transit service.
Furthermore, the problem with most current empirical work is that urban density threshold conclusions, in many cases, have not been formally controlled for factors such as household size, income, or the complementary influences of land-use mix.
This study will synthesize academic research and practitioner-based work that examines the relationships between transit design and urban form to develop an integrated transit and development typology and matrices indicating the relationships between transit and land-use variables. Variables will include the characteristics of transit service (such as mode, regional connectivity and service attributes such as frequency and speed) and the characteristics of urban form (such as neighborhood type, land-use mix, housing density and walkability).
This project will provide the research and documentation necessary to help professionals in the fields of transportation and urban design to bridge the gap between these separate disciplines and to create a clearly defined and shared terminology and methodology that enables planners and designers to better work together in finding integrated solutions to transit and land use.
This work will culminate in a publication summarizing the study results, an exposition of the methodology and matrices that lay out the findings in a readily accessible format.
Task 1: Literature Review
Several research studies have been conducted over the course of the last several decades regarding transit usage and urban form. These have been summarized by the Transit Cooperative Research Program (TCRP) Report 16, conducted by the Transportation Research Board.
The objective of this task is two-fold. First, formal empirical work conducted after the publication of TCRP 16 will be culled and summarized, with a focus on research efforts dealing with how land use form influences transit use. Second, this task will analyze and identify problems related to empirical studies providing residential density thresholds. In particular, the focus will be on formal measures developed to control for factors such as household income, household size, competing modes, as well as the robustness of the statistical/econometric methods employed.
Task 2: Land Use, Urban Density and Transit Form
One of the recommendations of TCRP 16 was to shift the focus from minimum density requirements to the “relationship between density and the cost at which transit service can be provided.” This requires taking into account the interactive nature of transit and urban form.
To date, research has focused on unidirectional impacts on transit and urban form (e.g., studies focusing on the impact of transit on urban form or vice versa). Such an approach implicitly ignores substitution and complementary effects between transit modes and their interaction with land use and density
The objective of this task is to develop an integrated approach to examining the relationships between transit design and urban form indicating the relationship between transit and land-use variables. The approach, compared to empirical studies currently available, will provide a formal framework to control for feedback effects between transit mode and urban form, which takes into account substitutability and complementarities. The following example provides a synopsis of what is meant by an integrated approach to transit and land use modeling.
Suppose a city has the density, according to Zupan's work, to support express bus with park and ride. If the city chose to upgrade or to build its transit system to handle this mode, that action could itself change land use, particularly near transit stations at first. This would increase the density in those vicinities and may make the chosen transit mode an incorrect choice, i.e, maybe the city should have chosen light rail. Likewise, if people move from their present locations nearer to transit stations, then this action would reduce densities in the original areas. If these areas of reducing density were served by a transit mode, say, local bus with frequent service, that mode may no longer be justified. Current and past research do not built this kind of response into his analysis, ignoring the feedback effects of the city's choice of a transit mode. This project seeks to develop a methodology for taking into consideration these feedback effects to specify the conditions under which transit modes would be feasible, providing a new contribution to this field of research.
This task will be accomplished in line with the recommendations provided by the TCRP Digest 7, which stated that “the interactive nature of transit and urban form, while complex, can potentially be conveyed through a balance of modeling work and carefully constructed empirical investigations that look at the joint influence of transit on residential location and ridership.”
Task 3: Transit Demand
Based on output from Task 1 and Task 2, an integrated approach to model transit demand and urban form will be developed. The methodology will specify the conditions under which transit modes will be feasible, while at the same time explicitly acknowledging built-in feedback responses into the analysis.
Task 4: Transit Supply
Residential density thresholds are relevant only if considered in conjunction with the cost and efficiency of the service. An integral part of the determination of transit supply is to identify which measures to employ to judge feasibility of given transit strategies. The choice of the cost measure impacts the suitability of different transit modes to diverse density and land use configurations.
This task will take into consideration the effect of using different metrics, such as farebox ratio, subsidy per rider, hours of travel time saved, and vehicle-miles of travel reduced in the evaluation of land use strategies.
Task 5: Final Report and Recommendations
The research will culminate in a final report that will lay out the proposed methodology, assumptions, and modeling technique employed. Findings will be summarized in a readily accessible format to enable planners and designers to better work together in finding integrated solutions.
Progress Reports – Progress Reports will be submitted on a monthly basis to the Research Center for processing. Reports will include the following sections:
Draft Final Report – An electronic copy of the draft final report will be submitted to the project manager no later than sixty (60) days before the end of the contract to allow sufficient time for editing and revisions. The draft final report will be edited for grammar, clarity, organization, and readability prior to submission to the Department for technical approval. The editor providing the review will sign a cover sheet attesting to such review prior to submission.
Final Report – Thirteen (13) hard copies of the final report, one (1) electronic version of the final (Word), and one (1) electronic version of the summary (Word) will be provided to the Research Office.
Other deliverables – Additional deliverables for this project will include the following:
Note: All materials printed under the contract will have the FDOT, USF and CUTR logos.
IV. Project Schedule
V. Project Budget
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. Budget requests includes salaries for clerical and administrative staff, postage, telephone calls, office supplies, general purpose software, subscriptions, and/or memberships.
No equipment is envisioned to be purchased under this project.
No travel expected to be necessary for this project.
VIII. Student Involvement
The proposed budget includes funds for a graduate student to assist with Task 1 and Task 2. The graduate student is currently pursuing a master in civil engineering and possesses modeling knowledge in both transportation demand forecasting and land use empirical analysis.
IX. Relationship to Other Research Projects
This study will build on previous TCRP reports, including TCRP Report 102, Transit Oriented Development in the United States: Experiences, Challenges and Prospects; TCRP Report 95, Chapter 15: Land Use and Site Design; and TCRP 16: Transit and Urban Form.
X. Potential Benefits of the Project
This project will provide the research and documentation necessary to help professionals in the fields of transportation and urban design to bridge the gap between these separate disciplines and to create a clearly defined and shared terminology and methodology that enables planners and designers to better work together and find integrated solutions.
This work will culminate in a publication summarizing the study results, the methodology, and matrices setting out the findings in a readily accessible format. Policy recommendations will also be provided for local, state and national officials.
National Center for Transit Research · at the Center For Urban Transportation Research · University of South Florida · 4202 E. Fowler Ave., CUT100 · Tampa, FL 33620-5375 · (813) 974-3120 · (813) 974-5168 · www.nctr.usf.edu · Comments: firstname.lastname@example.org