Research On Risk Distribution Of Freeway Accident Zone

After the freeway traffic accident, it is necessary for waiting for the traffic police’s arrival and investigation before the remove of the accident zone, and then the traffic is restored. Within the existence of the zone, traffic characteristics change and risk of the accident zone increases due to the emergence of traffic bottlenecks.In order to reveal driving risk of the accident zone quantitatively, in this paper, the influence factors of road traffic safety were analyzed and the risk factors set of freeway traffic accident zone was built first, and then the influence factors were identified using the DEMATEL-ISM method to determine the evaluation indexes of driving risk.By analyzing the process from formation to remove of the accident zone, the accident zone was divided in time. Using VISSIM, vehicle queue diffusion models of four-lane with single lane closure, six-lane with single lane, two lanes closure and eight-lane with single lane, two lanes and three lanes closure were established to study the influence of traffic volume on driving risk.Based on extension theory, the improved extension evaluation method is adopted to establish the freeway traffic accident risk time distribution model. Considering the problems of correlation function and weight determination in traditional extension evaluation model, the correlation function was modified and multiplication scale method was adopted to determine the evaluation index weight.Grading standard of risk factors was established through the analysis of the accident zone and reference to the simulation results, and the improved extension evaluation model was adopted to establish risk time distribution model of some typical four-lane, six-lane and eight-lane freeway traffic accident zone to verify the rationality and practicability of the model. The results show as the following rules, the driving risk of the accident untreated period is the highest and the driving risk of the accident finished treatment period is higher and the driving risk of the accident treatment period is the lowest. The results of the study can provide theoretical basis for the driver’s risk perception, behavioral decision and the freeway management staffs’ risk management.