Pedestrian Signal Safety - AAA Foundation for Traffic Safety

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time, the available green time would be adequate at the 3.00 ft./sec. scenario. The city’s use of a
greater minimum WALK time interval in this case implied a proactive policy to provide greater LOS to
pedestrians.
Key findings related to pedestrian WALK clearance time durations for the case study intersections
include the following:
• The White Plains, New York case study intersection did not have pedestrian intervals that
exceeded the available green time for any crosswalk and/or WALK time scenarios.
• The pedestrian intervals exceeded the available green times for the 3.00 ft./sec. scenario in
the case study intersection in Broward County, Florida, in one of three crosswalks and in four
of four crosswalks in the Minneapolis, Minnesota; Montgomery County, Maryland; and Salt
Lake City, Utah, case study intersections, respectively.
• The pedestrian intervals exceeded the available green times for both the 3.50 ft./sec. and
the 4.00 ft./sec. scenarios in the case study intersections in three of four crosswalks in
Montgomery County, Maryland and in four of four crosswalks in Salt Lake City, Utah.
INTERSECTION OPERATION ANALYSIS
CORSIM traffic simulations were developed for each intersection, with walking speeds of 3.00 ft./
sec., 3.50 ft./sec., and 4.00 ft./sec. used to determine the PCI. The impacts of these different walking
speeds on traffic operations were studied by determining the resulting LOS for each walking speed
under different vehicular traffic conditions.
LOS is a qualitative measure used to describe the operational condition of an intersection. LOS
utilizes a rating system ranging from A to F, with A signifying the highest LOS, characterized by
insignificant vehicular delay, and F signifying the lowest LOS, characterized by excessive vehicular
delay. By definition, an intersection operating at its capacity is operating at LOS E. The relationship
between vehicular delay and LOS at signalized intersections is shown in Table 15.
Table 15. Level of service at signalized intersections (Highway Capacity Manual 2000).
LOS
Control delay
(sec./vehicle)
A 80.0