Pedestrian Signal Safety - AAA Foundation for Traffic Safety

Table G-13. Salt Lake City, Utah intersection level of service under various peak-hour traffic volume
and pedestrian walking speed scenarios.
SUMMARY
Walking speed
scenario
-10 percent
volume
LOS (and average delay, in sec.)
Existing
volume
+5 percent
volume
+10 percent
volume
+15 percent
volume
3.00 ft./sec. C (23) C (24) C (25) C (22) C (26)
3.50 ft./sec. C (26) C (24) C (24) C (25) C (26)
4.00 ft./sec. C (21) C (22) C (23) C (24) C (25)
Major street LOS (and average delay, in sec.)
3.00 ft./sec. C (26) C (25) C (29) C (28) C (29)
3.50 ft./sec. C (25) C (26) C (27) C (27) C (29)
4.00 ft./sec. C (21) C (23) C (23) C (24) C (25)
Minor street LOS (and average delay, in sec.)
3.00 ft./sec. B (18) C (21) B (19) C (21) C (22)
3.50 ft./sec. B (19) B (20)* B (20)* C (21) B (20)*
4.00 ft./sec. C (21) C (22) C (22) C (23) C (24)
There were different environments between the two intersections with traditional signals and the
two intersections with countdown signals, which may account for differences in observed pedestrian
activity. With this caveat, the key results are as follows for Salt Lake City:
• MWS for younger pedestrians was 4.90 ft./sec. at the two TPS and 5.30 ft./sec. at the two PCD
signals. This difference was statistically significant.
• MWS for older pedestrians was 4.20 ft./sec. at the two TPS and 4.30 ft./sec. at the two PCD
signals. This difference was not statistically significant.
• MWS for older pedestrians was generally slower than for younger pedestrians by about
0.70 ft./sec. at traditional intersections and 1.00 ft./sec. at PCD intersections. The difference
in walking speeds between the two age groups was significant at both PCD signals and
traditional signals.
• Pedestrians with mobility impairments and without motorized or standard wheelchairs had
appreciably slower walking speeds—their mean was 3.60 ft./sec. compared to about 4.20 ft./
sec. for older pedestrians. A small sample size is recognized.
• Older pedestrians had a slower start-up time, but this will vary by intersection and leg of
intersection.
• A higher level of compliance (entering crosswalk on WALK display) was found with TPS with
younger pedestrians than with PCD signals. The reverse was true for older pedestrians.
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