Click for next page ( 27

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement

Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 26
26 was heavy pedestrian movement between a parking garage see previous bullet) was sight distance. There were several and a municipal building in the morning and afternoon). comments at individual sites where the adequacy of the In this situation, a signal is not needed for the pedestrian available site distance was questionable, especially when (although one participant noted that a signal may be on-street parking was present. needed for the vehiclesi.e., the signal needs to stop the pedestrians to allow the cars to move through the cross- Summary ing). The participants preferred having the vehicle data expressed in number of vehicles rather than gaps. In the 2003 MUTCD, the pedestrian warrant for a traffic The revised warrant should consider the operating or control signal considers several factors in determining the posted speed on the major roadway. need for a signal: pedestrian volume, gaps in vehicular traffic, Several participants commented on treating pedestrians and walking speed (which may be used to reduce pedestrian and vehicles equally. volume). Previous studies have documented the difficulty of One participant noted a safety concern with crosswalks meeting this warrant at intersections with pedestrian cross- on streets with four or more lanes. These crosswalks have ing needs. A review of the literature provided insight into the the potential for a "multiple threat" conflict, where a pedes- current warrant as well as the signal warranting practices of trian begins to cross in front of a vehicle stopped in the other countries. In reviewing all traffic control signal war- near lane but then has to avoid a vehicle in a subsequent rants, the research team noted several inconsistencies between lane that has not stopped. The participant advocated a dif- the pedestrian warrant and vehicle-based warrants. For ferent set of criteria for pedestrian signals on multi-lane example, the pedestrian warrant provides a single pedestrian streets. volume criterion, regardless of the major-street vehicle vol- The participants considered the following factors during ume being crossed, whereas vehicle-based warrants provide a the evaluation of the eight intersections: "sliding scale" where fewer minor-street vehicles are required Pedestrian volume (92 percent); as the major-street vehicle volume increases. Additionally, Traffic volume (77 percent); vehicle-based warrants permit a vehicle volume reduction to Speed (operating or posted) on major street (46 percent); 70 percent when major-street vehicle speeds exceed 40 mph Number of lanes on major street (23 percent); (70 km/h). The research team conducted a workshop to Other[opportunity for median refuge, crossing dis- gather engineering judgment about proposed revisions to the tance, or other possible treatment (23 percent)]; pedestrian warrant. In their judgment, most traffic engineers Crash history (8 percent); at the workshop believed the following should be considered Intersection versus midblock (8 percent); in a revised pedestrian warrant: width of roadway being Distance to nearest signal (8 percent); and crossed, the pedestrian volume, the major-street vehicle vol- Vehicular gaps available (8 percent). ume, and the major-street speed. The research team used When asked what other factors should be included in the these findings to develop the proposed recommendations for MUTCD, the only factor they listed (and that was not a revised pedestrian warrant for traffic control signals (see listed as being used in the evaluation of the eight sites-- Appendix B).