Influence of Main Road Alignment on Handling Stability of Runaway Vehicle on Truck Escape Ramp

Main road alignment exerts an influence on handling stability of a runaway vehicle to a certain extent, as rational designs of the main road alignment play an important role in ensuring that a runaway vehicle enters a truck escape ramp safely. Firstly, forces acting on the runaway vehicle on the main road are analysed, and the minimum curve radius value and the corresponding approach angle that can prevent lateral rollover and lateral slip are discussed. Secondly, a simulation software, TruckSim, is used to establish a simulation model of the runaway vehicle and the road, wherein the minimum curve radius value and the corresponding approach angle that can prevent lateral rollover and slip are taken as input parameters of the road model. Finally, the established simulation model of the vehicle and road is used to simulate the influence that three types of main road alignment, i.e. a straight line, a right curve and a left curve, respectively have on the handling stability of the runaway vehicle entering a truck escape ramp.