A Study of the Relationship between Rescue Time and Survival Rate of Traffic Accidents on Freeways using A Cox Regression Model

The rescue time of traffic collisions on expressways has a direct impact on traffic collision fatalities.Based on three consecutive years'collision records of an expressway in east China,the characteristics of rescue time were ana-lyzed in this paper.The impacts of rescue time on the survival rates were studied by using non-parametric estimation methods,and a survival-analysis model of the injuries was developed.Furthermore,factors of survival rates were ana-lyzed with Cox regression models.The results show that the survival rates of the injuries decrease with the increase of res-cue time.The survival rates can decrease to below 75% in about 14 minutes after the occurrence of collisions,so the inju-ries should be given necessary emergency rescue within 14 minutes.Meanwhile,further analysis of factors indicates the time of collisions is a risk factor of survival,and the risk of death in the nighttime is 3.46 times higher than in the day-time.