Pedestrian Signal Safety - AAA Foundation for Traffic Safety

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Table 17. Minneapolis/St. Paul, Minnesota: Total intersection level of service and average delay per
vehicle under various volume and pedestrian walking speed scenarios.
Walking
speed
scenario
3.00
ft./sec.
3.50
ft./sec.
4.00
ft./sec.
-10-percent
volume
Montgomery County, Maryland
LOS (and average delay, in sec.)
Existing
volume
+5-percent
volume
+10-percent
volume
+15-percent
volume
C (24) C (27) C (27) D (41) E (48)
C (24) C (27) C (27) C (31) C (32)
C (25) C (27) C (28) C (30) C (31)
Figure 10 and Table 18 show the total intersection LOS and ADPV for the Montgomery County,
Maryland case study intersection under various peak-hour traffic volume and pedestrian walking
speed scenarios. Table E-11 in Appendix E shows the intersection operational and geometric
characteristics for the Montgomery County case study intersection.
The modeled peak-hour volumes at the Montgomery County case study intersection ranged from a
decrease of 10 percent to an increase of 10 percent of existing peak-hour volumes. The existing LOS
at this case study intersection for the 3.00 ft./sec pedestrian walking speed scenario was at capacity
(LOS E) with a corresponding average delay of 60 sec. per vehicle.
When existing volume conditions were compared to a modeled increase of 5 percent above existing
volume conditions, the LOS designation (LOS E) did not change; however, there was a corresponding
increase in ADPV of approximately 9 sec. under the 3.00 ft./sec. walking speed scenario. An
incremental increase of another 5 percent of peak-hour volume (to 10 percent above existing
volumes) at the 3.00 ft./sec. walking speed lowered LOS from E to F and added 49 sec. to ADPV.
Thus, from existing volume conditions to a modeled increase of 10 percent over existing volumes,
there was a reduction of two LOS designations (from LOS D to F) and a corresponding increase of 58
sec. for ADPV.
Under the 3.50 ft./sec. and 4.00 ft./sec. walking speed scenarios, under existing volumes to an
increase of 10 percent over existing volumes, there was no change in LOS (LOS D); however, there
was a corresponding increase in ADPV of 6 sec. and 4 sec. under the 3.50 ft./sec. and 4.00 ft./sec.
walking speeds, respectively.
Thus, under the conditions analyzed, the 3.00 ft./sec. pedestrian walking speed, compared to the
3.50 ft./sec. and 4.00 ft./sec. pedestrian walking speeds, may have negatively impacted vehicular
traffic operations at the case study intersection to a much greater extent.
A discussion of LOS and AVD for the major and minor approaches is included in Appendix E to this
report. Table E-12 and Figures E-5, E-6, and E-7 in Appendix E show intersection delay for major and
minor street approaches at walking speeds of 3.00, 3.50, and 4.00 ft./sec. at the Montgomery County
case study intersection.