Research On Characteristics Analysis Of Car-Truck Heterogeneous Traffic Based On The Cellular Automata Model

With the domestic car ownership increases year by year, the vehicle heterogeneity significantly increased in the road. The phenomena of different vehicles driving reduces the efficiency of road network and declined the traffic capacity. Due to different sizes and driving characteristics of vehicles, the interference degree on surrounding vehicles are quite different in the process of driving. Must pay attention to the influence of heterogeneity traffic flow on the road traffic.Aiming at studying the heterogeneous traffic flow characteristics of cars and trucks, this paper adopted the modeling method of cellular automata, proposed three heterogeneous traffic flow cellular automata models in single-lane, slope, and two-lane. Further and systematic research was done at the car truck heterogeneous traffic flow characteristics by using the MATLAB language to program, simulating and numerical analysis.The single-lane model introduced the classic Gipps safe distance rules based on the NaSch model, refined the cellular size, considered the differences between car and truck in body length, maximum speed, acceleration and deceleration performance, and measured the model parameters using the NGSIM data value. Considering the effect of slope on car-truck driving behavior, the slope model was based on the rules of single-lane model and made improvements. The two-lane model created an extension of the single-lane model and added new lane changing rules.Conclusions are as follows:The impact of car-truck following combinations on traffic flow on single-lane is limited to a certain range (23 veh/km≤p<36 veh/km). The capacity increases with the increment of the proportion of car-following-car (CC) combination. While on the slope, the slope significantly influence on the traffic congestion, even just a 40m-long slope will aggravate congestion nearly 10%. With the percentage of trucks in two-lane increased gradually, the system flow, average speed, the critical density and the system’s unstable region will decrease.