TITLE:
Multi-Stage Pedestrian Crossings and Two-Stage Bicycle Turns: Delay Estimation and Signal Timing Techniques for Limiting Pedestrian and Bicycle Delay
AUTHORS:
Peter G. Furth, Yue (Danny) Wang, Michael A. Santos
KEYWORDS:
Pedestrian Delay, Traffic Signal Control, Multistage Crossings
JOURNAL NAME:
Journal of Transportation Technologies,
Vol.9 No.4,
October
10,
2019
ABSTRACT: Signalized intersections sometimes involve multistage pedestrian
crossings, in which pedestrians cross to one or more islands and then wait there
for a signal to continue. When signals are timed without attention to
pedestrian progression, pedestrian delay at multistage crossings can be very
long. This paper addresses two issues. First, pedestrian delay at multistage
crossings is rarely evaluated because there are no tools in the industry for
that purpose except microsimulation. We present a numerical method for
determining crossing delay with any number of stages and with the possibility
of multiple WALK intervals per cycle. The same method can be applied to single
stage crossings, to diagonal two-stage crossings where pedestrians may have
path choice, and bicycle two-stage turns. This method has been implemented in a
freely available online tool. Second, we describe several signal timing techniques
for improving pedestrian and bicyclist progression, and thus reducing their
delay, through multistage crossings. They include reservice for selected
crossing phases, left turn overlaps, having pedestrian phases overlap each other, and bidirectional
bicycle crossings which create path options for two-stage turns. Examples show
the potential for large reductions in pedestrian delay, often with little or no
increase in vehicular delay. In one example, the addition of a short pedestrian
overlap phase reduced average pedestrian delay at a 3-stage crossing by 82 s
while average vehicular delay increased by only 0.5 s.