关键词: 交通工程, 速度特性, 非线性回归, 高速公路, 能见度, 速度离散型, 预测模型

Abstract:

This paper explores the effects of traffic visibility on characteristics of vehicle speed, based on the traffic and road weather data of detectors positioned on the road segment between Jinshan and Wuhannan interchange of Jinggangao (G4) expressway in Hubei province. Focusing on the limited visibility weather element, this paper analyzes the effects of visibility on the mean speed and speed variation by fog or non-fog weather, or under fog weather condition with different visibility; speed characteristics are deeply explored from aspects of different factors of traffic lane, vehicle types and temporal hour, utilizing detailed traffic data containing traffic lane and vehicle type information. The comprehensive speed prediction model is built under fog weather condition considering several factors based on the classic traffic flow theory of Greenshield’s V- K relation, and the goodness- of- fit of the speed prediction model reaches 80% approximately. The research results of this paper can be useful or as a reference to impacts analysis of limited visibility on traffic safety, operation, and traffic capacity analysis, or decision making process of traffic control measures such as variable speed limit under adverse road weather conditions.

Key words: traffic engineering, speed characteristic, non- linear regression, expressway, visibility, speed variation, prediction model