Journal of South China University of Technology(Natural Science Edition) ›› 2022, Vol. 50 ›› Issue (7): 76-84.doi: 10.12141/j.issn.1000-565X.210658

• Traffic & Transportation Engineering • Previous Articles     Next Articles

Influence of the Combination Equilibrium of Horizontal and Crest Vertical Curves on Highway Safety

WANG Xiaofei1 LI Siyu1 CHEN Mi2 SHEN Tianjie1,3 LIU Yong4 XIAO Peng2   

  1. 1.School of Civil Engineering and Transportation,South China University of Technology,Guangzhou 510640,Guangdong,China
    2.Guangzhou Highway Engineering Group Co. ,Ltd. ,Guangzhou 510599,Guangdong,China
    3.Guangdong Provincial Key Laboratory of Modern Civil Engineering Technology,Guangzhou 510640,Guangdong,China
    4.Guangzhou Municipal Engineering Design and Research Institute Co. ,Ltd. ,Guangzhou 510062,Guangdong,China
  • Received:2021-10-14 Online:2022-07-25 Published:2021-12-17
  • Contact: 王晓飞(1980-),女,博士,副教授,主要从事公路路线及交通安全研究。 E-mail:xiaofeiw@ scut.edu.cn
  • About author:王晓飞(1980-),女,博士,副教授,主要从事公路路线及交通安全研究。
  • Supported by:
    the Natural Science Foundation of Guangdong(2022A1515011974);the Foundation of Guangdong Provincial Key Laboratory of Modern Civil Engineering Technology(2021B1212040003);the National Natural Science Foundation of China(51878297)

Abstract:

To throughly analyze the quantitative relationship between the equilibrium of horizontal and vertical alignment combination and road safety, aiming at the “horizontal curve(HC)+crest vertical curve(CVC)” (referred to as HC-CVC) alignment combination, this study collected the road alignment (a total of 477 km), the traffic data and accident data from 2011 to 2018 of four interstate roads in Washington, D.C. as training data and test data. According to the characteristics of horizontal and vertical alignment combination, the paper suggested to consider the dislocation value, the horizontal curve radius, the vertical curve radius, the length of horizontal curve and the length of vertical curve as variables to characterize the equilibrium of horizontal and vertical alignment combination. Three machine learning models, namely, Decision Trees, Random Forests and Extremely Randomized Trees, were applied for model training to analyze the influence of HC-CVC combination on the accident rate per 100 000 000 vehicle kilometers. The prediction and fitting accuracy of Random Forests is the highest among all models. What’s more, sensitivity analysis and numerical analysis based on Random Forests model show that: when the horizontal curve radius is greater than 2.8 km or the vertical curve radius is greater than 58 km, the increase of horizontal and vertical curve radius has little impact on the road safety. At the same time, this paper also studied the correlation between variables and accident and suggested the value range of the variables when the horizontal curve radius is small. The research conclusions can provide reference for the subsequent quantitative optimization design and safety improvement of horizontal and vertical alignment combination.

Key words:  highway alignment, road safety, combination of horizontal and crest vertical curves, equilibrium of horizontal and vertical alignment combination, machine learning

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