Purpose: Vehicle-pedestrian conflicts are com mon at road intersections when traffic lights change. However, the impact of traffic light on transportation safety and efficiency remains poorly understood. Methods: A tw...Purpose: Vehicle-pedestrian conflicts are com mon at road intersections when traffic lights change. However, the impact of traffic light on transportation safety and efficiency remains poorly understood. Methods: A two-stage study was used to survey the proportion of intersections with conflicting traffic lights and the related transpoilation efficiency and safety were evaluated as well. First, a cross-sectional study estimated the proportion of signalized intersections with conflicting left-turning vehicle-pedestrian traffic lights in Changsha city, China. Second, a natural experiment compared transportation efficiency and safety between intersections w让h and without conflicting left-turning vehicle-pedestrian traffic lights. Risky conflicts, where motor vehicles violated laws and failed to yield to pedestrians in crosswalk were used as a surrogate for transpoilation safety. The number of motor vehicles and pedestrians passing through the intersections per second and per meter were used to estimate transportation efficiency. Data were collected and analyzed in 2015 (from March to December). A search of on line news from domestic media sources was also conducted to collect pedestrian injury data occurri ng at the intersections. Results: About one-fourth (57/216) intersections had conflicting left-turning traffic lights (95% Cl: 20.5%, 32.3%). Risky vehicle-pedestria n con flicts were more frequently observed at in tersections with conflicti ng lights compared to those without (incidenee rate ratio (IRR) 3.13;pedestrians: IRR = 4.02), after adjusting for type of day (weekday vs. weekend), the time period of observation, and motor vehicles traffic flow. Intersections without conflicting vehicle-pedestrian traffic lights had similar transportation efficiency to those with conflicting lights after controlling for covariates (p > 0.05). The systematic review of news media reports yielded 10 left-turning vehicle-pedestrian crash events between 2011 and 2017, involving 11 moderate or severe pedestrian injuries and 3 fatal pedestrian injuries. Conclusion: Over one-fourth of road intersections in Changsha city, China have conflicting left-turning traffic lights. Conflicting traffic lights cannot improve transportation efficiency, but increase risky conflicts between vehicles and pedestrians.展开更多
基金the Natural Science Foundation of China (grant number. 81573260).
文摘Purpose: Vehicle-pedestrian conflicts are com mon at road intersections when traffic lights change. However, the impact of traffic light on transportation safety and efficiency remains poorly understood. Methods: A two-stage study was used to survey the proportion of intersections with conflicting traffic lights and the related transpoilation efficiency and safety were evaluated as well. First, a cross-sectional study estimated the proportion of signalized intersections with conflicting left-turning vehicle-pedestrian traffic lights in Changsha city, China. Second, a natural experiment compared transportation efficiency and safety between intersections w让h and without conflicting left-turning vehicle-pedestrian traffic lights. Risky conflicts, where motor vehicles violated laws and failed to yield to pedestrians in crosswalk were used as a surrogate for transpoilation safety. The number of motor vehicles and pedestrians passing through the intersections per second and per meter were used to estimate transportation efficiency. Data were collected and analyzed in 2015 (from March to December). A search of on line news from domestic media sources was also conducted to collect pedestrian injury data occurri ng at the intersections. Results: About one-fourth (57/216) intersections had conflicting left-turning traffic lights (95% Cl: 20.5%, 32.3%). Risky vehicle-pedestria n con flicts were more frequently observed at in tersections with conflicti ng lights compared to those without (incidenee rate ratio (IRR) 3.13;pedestrians: IRR = 4.02), after adjusting for type of day (weekday vs. weekend), the time period of observation, and motor vehicles traffic flow. Intersections without conflicting vehicle-pedestrian traffic lights had similar transportation efficiency to those with conflicting lights after controlling for covariates (p > 0.05). The systematic review of news media reports yielded 10 left-turning vehicle-pedestrian crash events between 2011 and 2017, involving 11 moderate or severe pedestrian injuries and 3 fatal pedestrian injuries. Conclusion: Over one-fourth of road intersections in Changsha city, China have conflicting left-turning traffic lights. Conflicting traffic lights cannot improve transportation efficiency, but increase risky conflicts between vehicles and pedestrians.
