Impacts of the 2009 MUTCD Changes in Pedestrian Walking Speed on Delay

In the 2009 edition of the Manual on Uniform Traffic Control Devices (MUTCD), the walking speed used to time the pedestrian clearance interval was reduced from 4.0 ft/s (1.22 m/s) to 3.5 ft/s (1.07 m/s) to better accommodate older and mobility-impaired pedestrians. This paper evaluated the effect of this change on vehicle delay at signalized intersections where the pedestrian requirement controls the minimum green time. An analytical relation was derived which showed that the maximum increase in green time, and therefore in the delay of stopped vehicles, equals d(1/3.5 − 1/4), where d is the curb-to-curb crossing width; it is independent of the initial green time, phasing plan, and traffic volumes. The relation was tested with a computer simulation of 30,000 two-phase intersections and a population of simulated pedestrians. In the simulation, the share of intersections that needed added green time increased from 19.0% to 25.7%, and the maximum increase in green time was 3.14 s on an 88-ft street. The average control delay increased by 0.27 s/veh over all intersections and by 1.03 s/veh over the affected intersections, and the level of service became worse at 2.3% of the intersections. For a pedestrian population with 20% older pedestrians, the share of pedestrians who could not finish crossing within the clearance time fell from 22.4% to 9.4%. The change gave a clear benefit to pedestrians at a small average cost in vehicle delay.