Search the USF Web site Site Map USF home page


Center Identification Number: 473-06

Project Title: Why People Cross Where They Do

Co-Principal Investigators: 
Xuehao Chu, Senior Research Associate
Phone: 813-974-9831
Suncom: 574-9831

Michael R. Baltes, Senior Research Associate
Phone: 813-974-9843
Suncom: 574-9843

Center for Urban Transportation Research
University of South Florida
Tampa, Florida
Fax: (813) 974-5168

External Project Contact: 
Martin Guttenplan
Phone: (850) 414-4906
Suncom: 994-4906

Systems Planning Office
Florida Department of Transportation

I. Project Objective

To understand the factors that determine where pedestrians cross streets. This will be done through a statistical calibration and validation process, involving collecting actual site characteristics and stated crossing locations by a sample of persons at a sample of sites. These variables will include those that are most important to the Department and local governments for the purpose of improving mobility, safety, and livability.

II. Project Abstract

The FDOT recently initiated a Multimodal Quality of Service Program to improve the methodologies contained in ART_PLAN so that they can be used to evaluate arterial level of service from a multimodal perspective. This initiative was motivated by two factors. At the national level, the Transportation Equity Act for the 21st Century (TEA-21) and the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) have led to a national desire to know the levels of service for automobile users as well as for transit users, pedestrians, and bicyclists. At the state level, the legislature passed HB-17, the Urban Infill and Redevelopment Act amending F.S. 163.3180 to state: "Local governments shall use professionally accepted techniques for measuring level of service for automobiles, bicycles, pedestrians, transit, and trucks. ... The Department of Transportation shall develop methodologies to assist local governments in implementing this multimodal level-of-service analysis. The Department of Community Affairs and the Department of Transportation shall provide technical assistance to local governments in applying these methodologies."

As part of this Multimodal Quality of Service Program, a street-crossing difficulty factor has been incorporated into the methodology for measuring transit level of service. This factor does not differentiate crossing at intersections and midblock locations and has not been tested on a real world population. This factor may not describe the crossing difficulty perceived by pedestrians at specific locations. In addition to this factor, two research projects are currently underway to develop such methodologies for street crossing by pedestrians: one for midblock locations and one for intersections. It is planned that the results from these two projects will be combined with an already developed methodology for walking along roadways to develop an overall pedestrian level of service for a highway segment or facility. This overall pedestrian level of service could potentially be used to replace the street-crossing difficulty factor in the transit level of service methodology.

In developing the two pedestrian methodologies, the two research teams and FDOT staff discovered a research gap in the Program with respect to street crossing by pedestrians. This gap concerns how measuring pedestrian level of service for midblock crossing relates to measuring pedestrian level of service for intersection crossing. In looking at a particular midblock location to cross the street and what quality of service a pedestrian would feel relative to making a decision to cross or not, what other options the pedestrian might have, and the distances between these options appear to be important factors. Such options are not being considered in the Program for pedestrian level of service related to street crossing. Nor do we understand why people cross a street where they do. The proposed research project will address these issues and will improve the Department's family of multimodal level of service measures.

III. Task Descriptions

Task 1 Determinants of Street-Crossing Locations

This task will involve identifying a set of potential determinants of why people cross a street where they do. From the Pedestrian Level of Service for Midblock Crossing: An Issue Paper, we already know a lot about the potential determinants for crossing streets at particular locations. This task will go beyond that by identifying the tradeoffs that pedestrians make in selecting alternative street-crossing locations. The researchers may use a variety of resources. At a minimum, the researchers will search and review the literature, including the literature review conducted as part of the Point Level of Service project currently underway as part of FDOT's Multimodal Quality of Service Program. In addition, the researchers may use group consensus among the research team, the Department's Project Manager, and designees. Finally, the research may use focus groups of pedestrians, if the other two approaches are determined to be inadequate. The researchers will document the results into a brief technical memorandum to the Department's Project Manager for review and comments. The researchers will address any substantive comments received and prepare a final technical memorandum.

Task 2 Sample of Sites and Participants

This task will involve selecting the sites of street blocks and participants for data collections from the Tampa Bay area. Participants will be limited to local residents who are 13 years or old. The exact number of participants or the exact approach to participant recruitment is open at this point. While it is not a desired approach to sample selection, the expected amount of effort on the part of participants may make it necessary to recruit the participants as temp workers. In terms of project management, recruiting temp workers involves less uncertainty than recruiting volunteers. In terms of cost, temp workers may cost more than volunteers.

It is important that the selected sites are representative of the sampling frame and have enough variation on each of the site characteristics. The sampling frame includes all roads in the Tampa Bay area that are minor arterials or higher. One way to get a representative sample of sites would be to assemble a computerized database on roadway segments with information on key characteristics such as the number of lanes and AADT and then to sample segments within each stratum defined by different combinations of these key characteristics. It is expected that a larger number of sites be selected for this project than for the Pedestrian Midblock Crossing Difficulty project. One reason is the number of variables will likely to increase once the consideration is expanded to more than one crossing location.

Once a preliminary set of sites is selected, they will be examined in the field for their static and dynamic characteristics. Static ones do not change temporally over a short period, while dynamic ones do. The number of lanes would be an example of a static characteristic. Traffic flow and traffic platooning would be examples of dynamic ones. Static ones can be collected before the stated-preference survey on site. Dynamic ones will be collected at the time of the stated-preference survey on site. First, the static characteristics will be checked for accuracy and collected. Second, more important, the dynamic characteristics will be observed so that they have adequate variation across the selected sites. The observation of dynamic characteristics will be done after these sites have been assigned to different days of the week and different hours of the day. If a total of 50 sites are selected, for example, the observation will be done on five different days of a week with 10 sites on each day. In addition, three periods of the day may be used: morning, mid-day, and afternoon.

Task 3 Data Collection

The researchers will collect two types of data in this task. One is data on the responses of the participants to the survey questions. The other is data on the dynamic characteristics synchronized with these responses. Based on the experience with the Pedestrian Midblock Crossing Difficulty project, collecting dynamic characteristics from videos should be avoided.

The researchers will provide information about the finalized set of sites along with the assigned day and period to the FDOT, which in turn will lay traffic counters at each site accordingly. These traffic counters will record dynamic characteristics of the sites measured at intervals of 1-5 minutes. The exact length of the intervals is open at this point. It will depend on how long the participants will be allowed to observe the sites before answering the survey questions. It is critical the clocks on the traffic counters be synchronized with the time instrument that the field survey workers will carry with them.

Following the installation of the traffic counters, the researchers will conduct a stated-preference survey of the participants at the pre-selected sites, days, and hours. If a total of 50 sites and 150 participants are selected, for example, we would have 30 participants on each day to cover 10 sites. We would then use two buses on each day with each bus carrying 15 participants and covering 5 sites.

The participants on each bus will be accompanied by field survey workers to a selected site. The participants in groups of 2-3 persons will be asked to observe and state individually where they would cross the street. The options available to them in the survey will include: the two intersections of the block, a crosswalk if available, and a pre-determined midblock location of the block. Individual participants will be standing at this pre-determined midblock location when responding to the survey questions. They will not actually step into the roadway. They will complete the survey and will then proceed to other pre-determined sites until all sites assigned to each bus are completed. The exact number of sites each participant will visit will depend on the total number of sites selected and the total number of participants. The field survey workers will record the times at which the participant groups start and end their observations.

Depending on the results from Task 1 on the determinants, additional dynamic characteristics may be collected during the survey. One potential example would be the number of turning movements as used in the Pedestrian Midblock Crossing Difficulty project.

Task 4 Statistical Analysis

This task will involve a statistical analysis of the data collected from the sites and participants. The researchers will use statistical tools and models that are most appropriate for the data collected. The focus will be to test the role of the pre-determined potential determinants in pedestrians' choice of street-crossing location. The testing will include the direction and magnitude of their effects as well as their statistical significance. The testing will take into account the fact that each participant will provide multiple data points for the analysis. To ensure that the results of this statistical analysis are robust, the researchers will test alternative specifications of the model, including variations in the variables.

Task 5 Implications

This task will involve drawing implications from the statistical analysis to the related planning activities and functional areas of the Department. These will include the relationship between measuring pedestrian level of service for street crossing at intersections and midblock locations, the methodology for measuring transit level of service, the planning for transit stops, and pedestrian safety for street crossing.

Task 6 Final Report

This task involves drafting a final report and revising it based on comments received from the Department's Project Manager and designated reviewers. The researchers will document the entire project including the methodology, data collected, lessons learned, and results from the statistical analysis. The researchers will develop a conceptual framework for combining the midblock and intersection methods. In addition, the researchers will discuss the implications of the project results to the Department's Multimodal Quality of Service Program, the planning of transit stops, and pedestrian safety planning in general.

IV. Student Involvement

Students will be used in selecting sites and participants and in collecting data.

V. Relationship to Other Research Projects

This project is part of FDOT?s research efforts on multi-modal level of service measures, including Pedestrian Midblock Crossing Difficulty funded through NCTR Year 1 and 2.

VI. Technology Transfer Activities/Peer Review

The results of this analysis will be provided to the FDOT through a series of quarterly progress reports and a final report. Copies of the final report will be widely distributed to various agencies, offices, and decision-makers in Florida.

VII. Potential Benefits of the Project

In addition to filling the research gap in the Department's Multimodal Quality of Service Program, the proposed project can also facilitate the Department's other planning activities and functional areas.

1) The results from the proposed project can help the Department improve the component of pedestrian street-crossing difficulty in the methodology for measuring transit level of service in the Program.
2) The proposed project can facilitate the planning of transit stops, particularly the location of transit stops. When these stops are located inappropriately, transit users may be more likely to take risks in order to catch a bus across the street.
3) The proposed project can have important implications in helping the Department understand how and when a pedestrian may go to a marked crosswalk in midblock locations.
4) The proposed project can help the Department address midblock dash as a serious pedestrian safety problem. During the 6-year period from 1994 to 1999, 1,597 pedestrians died while crossing a street at a midblock location. These represent half of all pedestrian fatalities during this period. More important, for every five pedestrian fatalities while crossing a street, one occurred at an intersection but four occurred at a midblock location. The proposed project can help identify alternative solutions to the safety problem of midblock dash.

This research will help improve tools for implementing the Urban Infill and Redevelopment Act of 1999. This project will continue to push Florida to the cutting edge of multi-modal level of service research in the nation.


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: