A Monte Carlo Simulation of Chain Reaction Rear End Potential Collisions on Freeways

In recent research on modelling road collisions very little attention has been paid to rear-end chainreaction collisions, which is characterized by more than two vehicles involved in a collision atthe same time. the core aim of the present research is to develop a methodology to estimate suchpotential collision probabilities based on a proactive perspective, where deceleration rate to avoidcollision is used as a surrogate safety measure. to consider the uncertainty of variables in estimatingthe n-vehicle rear-end collision, a methodology based on monte carlo simulation is proposed.to show the applicability of the proposed methodology, the ngsim trajectory database of i-80interstate freeway is used. the probability density function for drivers’ response time is developedthrough the analysis of 1534 car following situations detected in 45 minutes of movement. thepotential risk of two to five vehicle reaction collisions in a five vehicle platoon is estimated byrunning the simulation through 20 thousand substitutions of randomized generation values drawnfrom probability density function of response time and maximum available deceleration rate in afollowing outcome function. results show that avoiding rear-end collision should be consideredas a shared responsibility among the drivers in the platoon. as expected, the methodology considersprobability of n vehicles colliding at the same time decreasing as n increases. n-vehiclecollision is shown to be directly related to the clearance between the following vehicles within theplatoon and the speed of individual vehicles as well as the drivers’ reaction time and the maximumdeceleration rate available in individual vehicles. the proposed methodology is believed to actmore effectively than the ordinary methods, particularly if it is used to alarm drivers of vehiclessynchronized based on vehicular ad hoc network (vanet) methodologies.