Study On Driving Risk And Measurement For Freeway Work Zone

The early built freeway have entered the routine of maintenance, repair or reconstruction phase, as freeway work zone need to be closed some lanes, make the traffic flow more complex than normal section, and the driving risk is much higher than normal section. Therefore, analysis and measure the driving risk in work zone, provide a modern management mean for risk control in freeway work zone, so as to more effectively capture possible risks, and improve safety service level of work zone.This article studies the driving risk situation in freeway work zone, that is based on the VISSIM, finds that the traffic flow parameters are the main factors which affecting the driving risk, uses the orthogonal experiment method for traffic flow parameters sensitivity analysis, finds out the key variables, and according to the characteristics of freeway work zone which advance warning area, upstream transition area and activity area are the main traffic conflict zones, through the multiple linear regression method to build the risk assessment models of work zone of each region. The conflict rate is used as an evaluation index, the paper uses peaks over threshold(POT) model and the generalized pareto distribution(GPD) parameter method to build the driving risk measurement model which based on the non-accident statistic in freeway work zone, at the same time, study the threshold division method to improve the accuracy of measurement risk. In addition, analysis the deficiency of the risk measurement model, further excavate the sample’s data information, and build the expected shortfall risk measure model, which is of great significance to freeway work zone.In order to further prove the rationality of risk measurement model which based on the conflict rate and POT model, accident loss is used as the evaluation index, through the case of freeway work zone of Guilin to Liuzhou, we find out the conflict rate index is reasonable; In addition, traditional calculation methods are applied to estimate the risk value, compare it with POT model, the reliability of POT model calculation method is proved.