IATSS Research (Apr 2021)
Exploring pedestrian surrogate safety measures by road geometry at midblock crosswalks: A perspective under mixed traffic conditions
Abstract
Pedestrian safety is generally assessed using frequency of crashes, based on historical data, for a given transportation facility. However, the lack of good and reliable crash data has hampered its apposite analyses and in evaluating the effectiveness of pedestrian safety programs. To overcome this gap, traffic conflict technique (TCT) which relies mainly on the observations of critical traffic situations for safety analysis were developed. However, the applicability of TCTs and related measures under varying non-lane based heterogeneous traffic conditions prevailing in countries such as India is not widely explored. This paper attempts to evaluate pedestrian safety at urban midblock crosswalk using different surrogate safety measures, including vehicle crossing speed, post encroachment time (PET), yielding compliance of driver as well as pedestrian, and conflict rate. The number of conflicts were observed to increase as the average vehicle crossing speed increases, indicating that pedestrians are extremely vulnerable while crossing the road. The PET value for the smaller vehicles, such as two-wheelers and three-wheelers, is recorded to be lower than the heavy vehicles, such as trucks and buses. With the addition of one lane, there is a significant decrease in the PET value. The average PET values for the vehicle on eight-lane divided road is less than the six-lane divided, four-lane divided, and two-lane undivided roads. Further, the yielding compliance of the driver as well as of the pedestrian depends on the crossing speed of the approaching vehicle and the type of road geometry. Further, the rate and severity of conflicts increased with a decrease in the pedestrian crossing speed. The yielding behaviour of the drivers as well as the pedestrian's yielding compliance varies by location, highlighting the effect of individual and demographic characteristics on pedestrian crossing behaviour.
