Pedestrian Signal Safety - AAA Foundation for Traffic Safety

Pedestrians with Impairments
Pedestrians with discernable mobility or visual impairments were recorded separately, regardless
of their age. At the Salt Lake City intersections, 36 pedestrians with impairments were observed for
walking speeds during the study periods. The walking speeds categorized by impairments are listed
in Table G-5. These data are not stratified by age, location, or type of pedestrian signal because of
the small sample size.
Table G-5. Walking speeds of pedestrians with impairments, regardless of age, in Salt Lake City,
Utah.
Observed impairment Pedestrians MWS
Visually impaired 0 N/A
Mobility impaired (walked with a cane,
crutch, or push cart)
24 3.6
Motorized wheelchair assisted 6 6.1
Standard wheelchair 6 5.0
No pedestrians with visual impairments were observed during the study periods. MWS for pedestrians
with mobility impairments was only 3.60 ft./sec. This walking speed was similar to the 15th-percentile
speed for older pedestrians at the intersections.
Start-Up Times
Pedestrians who approached the intersection during the steady DON’T WALK (DW) interval and
waited for the WALK interval were observed to determine their start-up lost time. This is the time from
when the WALK indication is displayed on the pedestrian signal until the pedestrian leaves the curb
and starts his or her crossing. This start-up time is related to the pedestrian’s reaction to the signal
timing. However, there could be other factors, such as turning vehicles still in the intersection, that
may cause a pedestrian to delay their start across the intersection. No distinction was made between
those who waited for turning vehicles and those who simply did not react to the signal as quickly. Only
pedestrians who arrived prior to the onset of the WALK interval were included in this analysis.
Observations were recorded for pedestrians across the major leg of State Street and 200 South,
which was equipped with a PCD signal. Based on a sample of 71 younger pedestrians, younger
pedestrians had a start-up time of 1.70 sec. at this crossing. Based on a sample of 30 older
pedestrians, older pedestrians had a start-up time of 2.30 sec. This is a difference of .50 sec.
Compliance
Pedestrians at each intersection were observed during two to three hours of peak vehicle and
pedestrian activity by field observers. For each pedestrian, observers recorded the pedestrian
signal indication (WALK, FDW, or DW) that was displayed when the pedestrian entered the
intersection. Observations were recorded separately for younger pedestrians and those 65 and older.
Observations were recorded during the hours of peak vehicle activity because vehicle volumes at
intersections likely affect pedestrian compliance to the signal. This is related to the opportunity to
cross. That is, at an intersection with low vehicle volume, pedestrians are more likely to violate the
pedestrian signal because there are more available crossing gaps.
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