Pedestrian Signal Safety - AAA Foundation for Traffic Safety

Twenty-two pedestrians with mobility impairments were observed during the study period. MWS for
these pedestrians was 3.10 ft./sec. This walking speed was slower than the 15th-percentile for pedestrians
65 and older for all but one leg (Colesville Road and E. West Highway, major approach) of the
four 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 his or her 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 minor leg of Bethesda and Arlington (traditional),
the minor leg of Elm and Woodmont (countdown), and the minor leg of Colesville and E. West
Highway (countdown).
Based on a sample of 267 younger pedestrians at the three intersection legs, younger pedestrians
had an average start-up time of 2.19 sec. Based on a sample of 58 older pedestrians at the three
intersections, older pedestrians had a start-up time of 2.38 sec. This is a difference of .19 sec.
Compliance
Pedestrians at each intersection were observed during two hours of peak vehicle and pedestrian
activity using the PATH system. 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 three 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.
Pedestrians Under 65
Table E-6 shows the frequency and percentage of younger pedestrians entering during each signal
indication for the two intersections equipped with TPS.
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