Improving pedestrian safety at unsignalized crossings.

Auteur(s)
Fitzpatrick, K. Turner, S. Brewer, M. Carlson, P. Ullman, B. Trout, N. Sug Park, E. Whitacre, J. Lalani, N. & Lord, D.
Jaar
Samenvatting

There has been an increased emphasis on improving pedestrian safety. The desire to improve pedestrian safety extends to areas typically seen as being non-pedestrian-friendly, such as the higher speeds and wider roadways.With traffic conditions changing as traffic volumes and congestion increase, pedestrians’ ability to safely cross many roadways is affected. Recent developments in geometric design features, traffic control devices, and technologies may improve http://gulliver.trb.org/publications/nchrp/nchrp_rpt_562.pdf / http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_w91.pdf This report may be accessed by Internet users at pedestrian safety and access by addressing specific problems associated with roadway crossings. Although numerous treatments exist at unsignalized crossings, there is growing concern about their effectiveness. Thus, there is a need to identify and study selected treatments to determine their effectiveness. A recent research project jointly sponsored by TCRP and NCHRP was initiated to address this particular need. The research was conducted by the Texas Transportation Institute (TTI). The study had two main objectives: (1) to recommend selected engineering treatments to improve safety for pedestrians crossing high-volume, high-speed roadways at unsignalized intersections, in particular those served by public transportation; and (2) to recommend modifications to the Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD) pedestrian traffic signal warrant. The research team developed guidelines for use in selecting pedestrian crossing treatments for unsignalized intersections and midblock locations (Guidelines for Pedestrian Crossing Treatments, included in this report as Appendix A). Quantitative procedures in the guidelines use key input variables (such as pedestrian volume, street crossing width, and traffic volume) to recommend one of four possible crossing treatment categories: marked crosswalk; enhanced, high-visibility, or “active when present” traffic control device; red signal or beacon device; and conventional traffic control signal. The guidelines include supporting information for these treatment categories as well as examples and pictures of traffic control devices in each treatment category. The audience for these guidelines includes state, county, and city traffic engineers; transit agencies; roadway designers; and urban planners; as well as consultants for these groups and agencies. The research team developed and presented recommendations to the National Committee on Uniform Traffic Control Devices to revise the MUTCD pedestrian warrant for traffic control signals. The proposed revisions were derived from other vehicle-based traffic signal warrants and supplemented with data gathered during the study. The basis for the proposed pedestrian warrant revisions is that the number of pedestrians waiting to cross a street should be no greater than the number of vehicles waiting to cross or enter a street. Once this basis was accepted, then the existing vehicle-based warrants were used to derive comparable warrants for crossing pedestrians. In addition to traffic signal warrant revisions, the research team identified two other MUTCD sections that could be revised. The first revision is a minor addition that suggests the use of median refuge islands or curb extensions as alternatives to traffic control signals. The second revision is the inclusion of a new type of highway traffic signal,Pedestrian Traffic Control Signals, in the MUTCD. In accomplishing the two main study objectives, the research team also developed useful supporting information on various aspects of pedestrian safety at unsignalized roadway crossings. Two examples are the findings from the field studies on walking speed and motorist compliance. In total, 42 study sites were selected in seven different states for the field studies. The study sites were chosen so as to distribute the different types of crossing treatments in certain regions, so that data for a particular treatment were not collected from a single city. The field studies included nine different types of pedestrian crossing treatments. A total of 3,155 pedestrians were recorded during the field study. Of that value, 81 percent (2,552 pedestrians) were observed as “walking.” The remaining 19 percent of the pedestrians (603) were observed to be running, both walking and running during the crossing, or using some form of assistance (such as skates or bicycles). Comparing the findings from the TCRP/NCHRP field study with previous work resulted in the following walking speed recommendations: 3.5 ft/s (1.1 m/s) for the general population and 3.0 ft/s (0.9 m/s) for the older or less able population. The research team chose motorist compliance (that is, yielding or stopping where required) as the primary measure of effectiveness for engineering treatments at unsignalized roadway crossings. In addition to collecting motorist yielding behaviour for general population pedestrians, the data collection personnel also staged street crossings to ensure consistency among all sites as well as adequate sample sizes. The study found that the crossing treatment affects motorist compliance. Those treatments that show a red signal indication to the motorist have a statistically significant different compliance rate from devices that do not show a red indication. These red signal or beacon devices had compliance rates greater than 95 percent and include midblock signals, half signals, and high-intensity activated crosswalk (HAWK) signal beacons. Nearly all the red signal or beacon treatments evaluated were used on busy, high-speed arterial streets. Pedestrian crossing flags and in-street crossing signs also were effective in prompting motorist yielding, achieving 65 and 87 percent compliance, respectively.However, most of these crossing treatments were installed on lower-speed and lower-volume, two-lane roadways. The measured motorist compliance for many crossing treatments varied considerably among sites. Number of lanes being crossed and posted speed limit were other factors in addition to type of treatment influencing the effectiveness of the crossing treatments. (Author/publisher) TCRP Web-Only Document 30 or NCHRP Web-Only Document 91, consists of the appendices to TCRP Report 112/NCHRP Report 562 (Improving Pedestrian Safety at Unsignalized Crossings) and can be found at: http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_w91.pdf See also C 36934.

Publicatie

Bibliotheeknummer
C 36933 [electronic version only]
Uitgave

Washington, D.C., National Research Council NRC, Transportation Research Board TRB / National Academy Press, 2006, 99 p., 65 ref.; Transit Cooperative Research Program TCRP Report 112, Project D-8 - ISSN 1073-4872 / ISBN 0-309-09859-9 / National Cooperative Highway Research Program NCHRP Report 562, Project 3-71 - ISSN 0077-5614 / ISBN 0-309-09859-9

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