Simulation and Analysis of the Buffer Function of Freeway Greening on Out-of-Control Vehicles

Daiquan Xiao
Huazhong University of Science and Technology School of Civil Engineering and Mechanics No.1037, Luoyu Road, Wuhan, China

Zhihe Wen
Huazhong University of Science and Technology School of Civil Engineering and Mechanics No.1037, Luoyu Road, Wuhan, China

Xuecai Xu
Huazhong University of Science and Technology School of Civil Engineering and Mechanics No.1037, Luoyu Road, Wuhan, China

Željko Šarić
University of Zagreb Faculty of Transport and Traffic Sciences Vukeliceva 4,1000 Zagreb, Croatia

Abstract

Freeway greening and traffic safety has aroused more and more attention. The purpose of this study is to investigate the role of flexible green planting in buffering out-of-control vehicles. The stopping distances of vehicle rushing into greening were tested at 8 group of initial speeds range from 5km/h to 40km/h in green belt, and a simplified mathematical model was built up to simulate the buffering process. The results indicated that the greening plants have certain buffering effect on vehicles and alleviate the crash damage within 30m of stopping distance for the vehicles under 40km/h, while the simplified mathematical model could reflect the buffering process of the plants actually by simulating the speed attenuation process, and it was found that the two types of resistance produced by the plants, i.e. counterforce of plants trunks and friction of branches and leaves, are the major factors during the vehicle deceleration.