Development of Fuzzy-Based Bus Rear-End Collision Warning Thresholds Using a Driving Simulator

The purpose of this paper is to develop rear-end collision warning thresholds with appropriate values of parameters for busses driving on freeways. Based on a bus-driving simulator, we design a simulation scenario of car following with emergency braking on freeways. Bus drivers working with a bus company are recruited to manipulate the simulation. The perception-reaction time, braking deceleration rate, and buffer of bus drivers' responses to a lead vehicle suddenly braking are collected and analyzed as parameters. Results indicate that not all the subjects have the same value in each parameter. Hence, the values of parameters in the bus rear-end collision warning threshold equations should be differentiated from various bus-driving characteristics. This paper further uses a fuzzy set theory to develop the safety membership function of each parameter and deduces 27 warning threshold equations. By these threshold equations, a rear-end collision warning algorithm for busses driving on freeways is also recommended.