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Center Identification Number:  77708   


Project Title:  Development of Alternative Measures of Transit Mode Share  


Co-Principal Investigators:


Xuehao Chu, Senior Research Associate
Phone: (813) 974-9831


Steve Polzin

Phone: 813-974-9849





Center for Urban Transportation Research

University of South Florida

Fax: 813-974-5168


External Project Contact:     


Ike Ubaka

Public Transportation Office / Transit Planning





I.  Project Objective/Problem Statement

There is a growing debate within the transit industry about the validity of the traditional measure of transit mode share used by the U.S. Census Bureau to describe transit usage relative to other modes. Many in the industry believe that the traditional measure does not accurately reflect the level of transit usage because it does not take into account the temporal and spatial availability of transit services. To address this issue, the transit industry would like to see the development of alternative measures of transit mode share that better reflect transit’s role in providing mobility relative to other modes.

This project is designed to accomplish four objectives: 1) to examine current measures of transit mode share, both from the decennial census and from other data sources; 2) to formulate and evaluate alternative measures of transit mode share; 3) to determine a baseline transit mode share in Florida; and 4) to assess the feasibility of mode share as a performance measure. One of the criteria for evaluating the alternative methods will be whether or not original data collection is required. If it turns out that the “superior” alternative requires collection of new data, the next best alternative that does not require original data collection would be used in determining the baseline transit mode share. In that case, the collection of original data and the application of the superior alternative would be accomplished in a separate future research effort.

II.  Objectives/Tasks

The proposed scope of services for this project consists of the following tasks.

Task 1. Examine Current Measures

This task will review the literature on measuring transportation mode shares and will examine current measures of transit mode share. The focus will be on the treatment of transit and other modes in measuring mode shares. Other problems with measuring transit mode share will also be covered. The result of this task will also help formulate alternative methods in the next task.

Task 2. Formulate Alternative Methods

This task will formulate alternative methods for estimating transit mode share. These methods will differ in some or all of the following dimensions:

●  Availability of data (original data collection required or not required).
●  Measure of travel (persons or person trips or person miles),
●  Period of travel (peak versus whole day),
●  Level of transit availability (everywhere or where transit is available or where transit is competitive),
●  Type of transit service (fixed-route or all service types),
●  Geography (statewide or urban areas or intermodal corridors in urban areas),
●  Modes of travel (transit versus auto or transit versus all modes),
●  Purpose of travel (commuting or all),
●  Collection of data (stated by survey respondents or observed directly), and
●  How the question is asked when data are collected through surveys (usual mode of commuting last week or main mode for every trip on a trip day).

The outcome will be a set of alternative methods for measuring transit mode share to be evaluated in the next task.

Task 3. Evaluate Alternative Methods

This task will develop and apply a set of evaluation criteria to the alternative mode share methods from Task 2 for the purpose of identifying the preferred alternative. These criteria will include but may not be limited to the following: 1) the statistical ability of each method to detect temporal changes in transit mode share; 2) the sensitivity of the method to the level of transit service within the subject geographic area; 3) the cost of implementing each method. The outcome is one recommended method for FDOT to measure transit mode share.

A significant portion of this task and this project will test measures of transit mode share that account for the spatial and temporal availability of transit. This consideration of spatial availability will be accomplished by linking statewide GIS transit route information from the Florida Transit Information System (FTIS) with the National Household Travel Survey at the individual household level and the Journey to Work data from the 2000 Census at the block-group level. This task will also consider the feasibility of measuring transit mode share that takes into account spatial availability using the American Community Survey.

Task 4. Establish Baseline Measures

This task will establish a baseline measure of transit mode share in Florida. The basis of the baseline will depend on the outcomes of Task 3. If the recommended method from Task 3 does not require original data collection, it will be used for the baseline. Otherwise, the next best alternative method that does not require new data collection will be used. The outcome is estimated transit mode share, with which future conditions can be compared.

Task 5. Assess Transit Mode Share as a Performance Measure

This task will determine whether transit mode share is an appropriate metric as a transportation performance measure for Florida. To accomplish this, the task will evaluate whether transit mode share as a metric has the basic characteristics that an effective performance measure should have. These include stakeholder acceptance, linkage to goals and objectives, clarity, reliability, credibility, timeliness, and integration into agency decision-making processes. The task will also review applications of using transit mode share as a performance measure elsewhere either at the state level or at the sub-state regional level. The outcome will be information for decision-makers on whether FDOT should adopt transit mode share as a performance measure.

Task 6. Prepare Final Report

This task will document the research on each of the four stated objectives and present the outcome from accomplishing each objective. The outcome of this task is the “Final Report.”

III. Deliverables

This project will have four deliverables. A technical memorandum will be prepared to document Tasks 1-3. Another technical memorandum will be prepared to document Tasks 4-5. An electronic copy of each technical memorandum will be sent to the Research Office and the Project Manager via e-mail. The third deliverable will be the “Final Report”, in both draft and final forms. Once approved by the FDOT Project Manager and the Research Office, 12 copies of the “Final Report”, an electronic version, and an electronic version of the project summary will be submitted to the Research Office. A total of 12 copies of the “Final Report” will be submitted to the FDOT Project Manager. Finally, a PowerPoint presentation will be prepared and sent to the Project Manager via e-mail on research objectives, methodology, and findings

The Project Manager will be updated on the progress of the project through the Quarterly Progress Report sent via e-mail.


IV.  Project Schedule



Months from Notice to Proceed

















Current Measures




































































Performance Measure

















Final Report

















V.  Project Budget


Development of Alternative Measures of Transit Mode Share

Budget Categories


Center Director Salary


Faculty Salaries

$ 44,739

Admin. Staff Salaries


Other Staff Salaries


Student Salaries

$ 22,799  

Staff Benefits

$ 26,589

Total Salaries and Benefits

$ 94,127



Permanent Equipment


Expendable Property/Supplies

$     511

Domestic Travel

$     600

Foreign Travel


Other Direct Costs


Total Direct Costs

$ 95,238

Indirect Costs

$   4,762

Total Costs



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.


VI. Equipment

No equipment is envisioned to be purchased under this project.

VII. Travel

As part of Tasks 2 and 3, the project team will visit 2 corridors in Florida to investigate the measurement of transit mode share at the corridor level. The locations of the corridors are yet to be identified during the project. It is anticipated that the results of this research would be presented to the transit industry in Florida at the annual Florida Transit Association meeting, the location of which is not known at this point. It is expected that 2 members of the project team will travel together with a total of 6 person trips.



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 · · Comments: