Numerical study of the stopping distance for runaway vehicle on truck escape ramp by using the improved equation of car driving

Abstract

The stopping distance of the runaway vehicle on the mountain road directly affects the length design of the arrester bed. Since the subsidence depth of runaway vehicle wheel on the arrester bed is neglected in the past researches, the stopping distance estimated by the vehicle driving equation is not accurate. The purpose of this paper is to supplement the influence of subsidence depth on rolling resistance and the influence of mountain highway altitude on air resistance, and improve the estimation accuracy through improved vehicle driving equation. Firstly, the formula for fitting the subsidence depth is established, and the formula for calculating the pushing resistance and compaction resistance is added. Considering the influence of the altitude of the mountain road on the air resistance, the formula for calculating the corrected air resistance and the air lift is added too and the improved vehicle driving equation is generated. Secondly, a simulink model is established based on the improved vehicle driving equation and determine the attester bed entering position and the initial entering speed of the runaway vehicle. Finally, the simulation model is run and analysed. The results show that the error rate of the simulation results is less than 8.0% compared with the full-scale test data. Compared with original equation, the shortening rate of the stopping distance is up to 85.59%.

Location of Emergency Escape Ramps on Two-Lane Rural Highways Based on the Fuzzy Multicriteria Decision-Making Method

“…Nowadays, over time and the implementation of the developments obtained after many years in communication roads, the vast volume of these roads, especially in Iran, where most of the densely populated and busy sections are mountainous, always have particular characteristics and are separated from the roads that exist in the plains and deserts. e installation of an emergency escape ramp can somehow be a development idea for better use of the roads in question to prevent accidents that lead to further damages [1][2][3][4]. e emergency escape ramp is a traffic device that enables vehicles with braking problems to stop safely.…”

Decelerations of Passenger Vehicles on Gravel Arrester Beds

“…The only publicly available study that deals with experimental measurements of the deceleration of light passenger vehicles in gravel-filled arrester beds is the study of Cocks and Goodram [11], which dates back to the early 1980s. Some recent studies [20][21][22][23] have dealt with numerical modelling and the simulation of vehicle motion on various forms of gravel areas and obtained results that differ from those acquired experimentally. Therefore, the purpose of the work presented in this article was to experimentally test the suitability of gravel-filled arrester beds for reducing the speed of passenger cars if they leave the roadway on a highway and to apply this knowledge to building arresting beds and increasing the safety of exit lines on highways.…”