Abstract: An accurate evaluation of the effect of a bus stop near an access for an expressway on car travel time on the main road is the basis for taking effective traffic management and organization measures. Based on the traffic characteristics analysis of bus stops and accesses,taking a bus stop located at the upstream of an exit as an example,a semi parametric proportional hazards model(Cox model) was used to analyze the association between car travel time and risk factors. Survival probability of sensitivity to individual covariates was illustrated.Resultsshow that four variables are significantly related to the car travel time. The model can be used to precisely estimate the distribution of car travel time and predict temporal shifts in car travel time due to the change of some factor.