Comparison of exposure in pedestrian crash analyses : a study based on zonal origin-destination survey data

Abstract

In recent years, the importance of exposure for pedestrian crash analysis has received increasing attention. Unlike the case of motor vehicle crashes, the definition of exposure for pedestrian crash analysis is sometimes vague and the mechanism behind the association between exposure and pedestrian crash is often ambiguously defined. In this study, the number of roads crossed and walking distance is estimated using an integrated trip assignment method at the aggregate level. The number of walking trips are also considered and compared with the distance travelled and road crossing based exposure using joint probability models. Results show that models using the road crossing based exposure approach provides the best model fit. It is found that the number of roads crossed is the most sensitive to vehicle-pedestrian collisions, as it is more strongly correlated to potential vehicle-pedestrian interactions. The results also indicate that the sensitivity of number of road crossed could vary with road types, and road safety measures for pedestrian protection should be widely implemented on low-grade roads.