Abstract
The truck operation of freeway has an impact on traffic safety. In particular, the gradually increasing in truck proportion will inevitably affect the freeway traffic operation of different traffic volume. In this paper, VISSIM simulation is used to supply the field data and orthogonal experimental is designed for calibrate the simulation data. Then, SSAM modeling is combined to analyze the impact of truck proportion on traffic flow parameters and traffic conflicts. The serious and general conflict prediction model based on the Adaptive Network-based Fuzzy Inference System (ANFIS) is proposed to determine the impact of the truck proportion on freeway traffic safety. The results show that when the truck proportion is around 0.4 under 3200 veh/h and 0.6 under 2600 veh/h, there are more traffic conflicts and the number of serious conflicts is more than the number of general conflicts, which also reflect the relationship between truck proportion and traffic safety. Under 3000 veh/h, travel time and average delay increasing while mean speed and mean speed of small car decreases with truck proportion increases. The mean time headway rises largely with the truck proportion increasing above 3000 veh/h. The speed standard deviation increases initially and then fall with truck proportion increasing. The lane-changing decreases while truck proportion increasing. In addition, ANFIS can accurately determine the impact of truck proportion on traffic conflicts under different traffic volume, and also validate the learning ability of ANFIS.
Highlights
Introduction and Literature ReviewWith the prosperity of logistics industry in China, the volume of trucks on freeway has been increasing and the freeway trafc safety is more and more obvious [11, 30]. e factors impacting tra c safety on freeway are numerous, including drivers, vehicles, environment, and road alignment
The purpose of this paper is to explore the impact of truck proportion on traffic flow parameters and traffic conflicts and lay the foundation of studying the correlation between safety and truck proportion
Due to the actual conditions, the tra c data obtained through eld surveys can hardly cover the tra c ow status under di erent tra c conditions of the freeway. e main purpose of this paper is to study the in uence of truck proportion on freeway tra c safety, so the more and more tra c parameters under di erent tra c conditions are needed to be obtained
Summary
Introduction and Literature ReviewWith the prosperity of logistics industry in China, the volume of trucks on freeway has been increasing and the freeway trafc safety is more and more obvious [11, 30]. e factors impacting tra c safety on freeway are numerous, including drivers, vehicles, environment, and road alignment. According to statistics from the Tra c Management Bureau of the Public Security Ministry [25], a total of 50,400 road accidents involving trucks were reported, causing 25,000 deaths and 46,800 injuries, which accounted for 30.5%, 48.23%, and 27.81% of the total number of auto liability accidents, respectively It is much higher than the truck proportion to total number of vehicles. A number of studies had examined the impact of trucks on tra c safety based on history crashes data [26] by using various statistical models such as univariate Poisson-lognormal (UVPLN), multivariate Poisson (MVP), and multivariate Poisson-lognormal (MVPLN) regression [5]. A mixed (random parameters) logit model [16] was used to study the injury-severity distributions of accidents on highway segments combined with tra c ow Journal of Advanced Transportation characteristics, which all showed that the presence of higher truck percentages and the sheer number of trucks might have a slowing effect on travel speeds which would tend to decrease the injury-severity of accidents. e literatures mentioned the impact of traffic safety combined with truck proportion via traffic crashes data a little rather than center on the safety via truck proportion
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
