Effect of Traffic Signal Countdown Timers on Pedestrian Crossings at Signalized Intersection

Abstract

Installations of signal countdown timers (SCTs) adjacent to the traffic signal heads are on the rise at several intersection locations in India. These SCTs provide information related to the time left for a particular signal phase and thus expected to help the driver take better decision. But no scientific studies were carried out before their installations at intersection locations. Pedestrian countdown timers (PCTs), which work on the same principle as SCTs found to be effective in terms of reducing pedestrian violations, pedestrian-vehicle conflicts as they provide information about the time left for a particular phase. These PCTs are becoming common at urban intersections in Indian cities, but not in very large numbers as their installation will require an additional infrastructural cost. In order to assess whether the SCTs themselves can facilitate the pedestrian movement at signalized intersections or not, the present study attempts to observe their effect on pedestrian movements at zebra crossing locations. When countdown timers were present, a higher percent of the cycles were observed to have some sort of red light violations (RLVs) as compared to the situation when the timer was absence. Average red light violations per red light cycle were found to be 3.2 and 2 RLV/RLV cycle in the presence and absence of signal countdown timers, respectively at intersection 1. The similar trend observed in intersection 2 (6.7 and 2.5 RLV/RLV cycle in the presence and absence of signal countdown timers respectively). SCTs did not have any effect on pedestrian waiting time on curb or pedestrian speed during crossing. These digital timers increased pedestrian violations. In the absence of SCT, less number of pedestrians was observed to cross the road during green and yellow phase, whereas higher number of pedestrian crossings was found during the initial portion of red phase. Overall, it was observed that rampant installation of these SCTs at major urban signalized intersections without conducting extensive studies would detrimentally affect the pedestrian movements making the crossing process complex and unsafe.