Research on the Influence of Freeway Truck Mixing Rate on Traffic State

As the high-speed freight passage between cities, the freeway plays an important role in promoting the economic development along. Freight occupies a large proportion of the traffic on freeway. The characteristics of trucks, such as big size, poor flexibility, slow speed, would make a certain impact on the traffic state. In this paper, based on the traffic survey data of typical sections in mountainous areas, regression was used to study the relationship between truck mixing rate and traffic flow parameters. By clustering analysis of traffic flow data, the distance-based K-means algorithm was adopted to demarcate the freeway traffic state and determine the threshold of the influence of truck mixing rate on the traffic state. The results show that with the premise of a certain speed and density, when the truck mixing rate is less than 0.35, a good traffic state is identified; when the rate is higher than 0.35, a greater impact on the traffic flow is spotted, leading to a high possibility of traffic accidents. Hence, it is concluded that freight traffic should be reasonably controlled to enter the freeway.