Midblock Signalled Pedestrian Crossing - Alternative Controller Algorithms

Abstract

Observation at midblock signalled pedestrian crossings in Malaysia showed that
violation of the red signal aspect by both the motorists and pedestrians is close to
70 %. Motorists may travel on the red signal aspect when there is no pedestrian
on the crossing. Pedestrians are also observed to cross in vehicle gaps at the
crossings during the right of way to vehicles. Such behaviour is dangerous
especially at a system where the traffic movements rely on the signal aspects
shown to them. Four alternative algorithms were designed in order to enhance
the operation and safety of users at the midblock signalled pedestrian crossings in
Malaysia. The objectives are to increase pedestrian safety and drivers compliance
with the signal. The developed strategies required detectors to register the vehicle
and pedestrian demands. Algorithms were designed to compute the appropriate
time to start and terminate the vehicle and pedestrian precedence. The applied
computation aimed to limit vehicle delay and to ensure that vehicle saturation
flow does not exceed 85 % of the road capacity. Apart from the vehicle demands,
the developed strategies also attempt to emphasis on the requirement and limits
of pedestrian behaviour. Four measures of performance are compared and
evaluated. These measures are the percentage of vehicles crossing on the red
man, pedestrian mean delay, mean cycle times and vehicle mean delay. The
measures of performance of all algorithms are evaluated using a fully calibrated
and validated simulation program. All of the new strategies increase the
pedestrian compliance and balance. This indicates that the present system does
not respond satisfactorily to the gaps in vehicle flow and may contribute to the
users disrespect of the system.