Comparing two countdown pedestrian signal displays in the District of Columbia

According to the Manual on Uniform Traffic Control Devices (MUTCD), Countdown Pedestrian Signals (CPS) shall only be displayed during the clearance interval (FLASHING DON´T WALK - FDW) of pedestrian signals. The primary purpose of this CPS display is to inform pedestrians of the remaining time for crossing a road controlled by the signal, to discourage them from starting, and to inform those who are already on the way of the remaining time before the beginning of the DON´T WALK (DW) interval. The general literature on CPS is conclusive that CPS is better understood than the conventional pedestrian signals. In the District of Columbia the CPS display starts at the onset of the Steady WALK (SW) interval and continues through the FDW interval. It is not certain whether this CPS display has any advantage over the standard display as prescribed by the MUTCD. In this research a comparative field study of both types of countdown displays at twenty-five (25) intersections in the District of Columbia was conducted. The results of the evaluation showed that at the majority of the intersections studied, there were no statistically significant differences in pedestrian crossing behaviors (using 5% significance level) due to the type of CPS display.