Left turn across path and opposite direction accidents in China: CIDAS accident study

Abstract

Left Turn Across Path with Opposite Direction (LTAP/OD) conflicts are one of the most common crash types at intersections. The research aims to reveal the general and dynamic information about the conflict for the most relevant street layouts for each conflict configuration of the LTAP/OD accidents involving passenger cars, motorcycles and Ebikes. The analysis was based on 276 LTAP/OD accidents collected by China In-Depth Accident Study (CIDAS 2011–2019). The LTAP/OD accidents include 44 car-to-car conflicts, 157 car-to-motorcycle conflicts and 75 car-to-Ebike conflicts. Most of accidents belonging to three types were observed at the W0 street layout without green belt separating the oncoming lane and no offset lane between the turning car and the oncoming traffic, the main distance between both vehicles in the beginning of the critical situation being about four meters, occurring in the clear day with no rain and at junctions lighted either because of daylight or based on street lighting. In terms of the turning car initial speed, the range is between 15-30 km/h for most car-to-car and car-to-motorcycle accidents but 30-40 km/h for most car-to-Ebike accidents. As for the collision speed, this range is between 10 and 20 km/h for car-to-car and car-to-Ebike accidents and between 10 and 25 km/h for car-to-motorcycle crashes. Based on the distributions of objective motorcycles’ and Ebike's positions in collisions with passenger cars, the maximum longitudinal distance is 60 m for both two types of accidents and the maximum lateral distance ranges from -20 m to 20 m and from -15 m to 15 m, respectively.