Modeling And Analyzing Of Mixed Traffic Flow On The Urban Road Section Based On Social Force

Mixed traffic is a typical feature of the urban road traffic in China, and its unique character has become an important factor to the traffic congestion and traffic accident. Base on the interaction mechanization of vehicles and the basic hypothesis of social force model, a dynamics model of mixed traffic flow has been established in this paper. The vehicles are affected by the inner and outer forces, by which almost all of the traffic actions of the vehicles have been affected, synchronously, and the inner forces derive from the drivers'appetency of driving with the best velocity while the outer forces derive from the affection of the other vehicles and the borders of the road. Qualitative and quantitative analysis of the inner and outer forces have been implemented in this paper, based on which a social force model for the motor vehicle traffic, the bicycle traffic and mixed traffic has been established respectively. By simulation, we come to the conclusions as follows:1. By the simulation of the lane-changing and overtaking behavior of the motor vehicle, we found that the traffic capacity can be promoted due to the lane-changing and overtaking behavior of the vehicle when the traffic density is lower, while it is not suitable for the situation when the traffic density is higher.2. By the simulation of the bicycle traffic when there is no segregation facilities existing between the bicycle and motor vehicle traffic, we found that the social force model of bicycle traffic can reflect the relationship among the traffic capacity, the average speed and the traffic density. The result of the simulation shows that the average speed of the vehicle fluctuates weakly with the traffic density increase when the traffic is not congested.3. By the probability of the sudden braking, while the mixed traffic flow in a urban road section has been simulated, the traffic safety risk of the mixed traffic flow has been analyzed, from which we come to the conclusion that the risk of the mixed traffic potential danger is proportional to the traffic density. For the mixed traffic flow, with the motor vehicle traffic density decreasing, the velocity and the probability of the non-motorized vehicle driving into the motor vehicle lane will increase, and the probability of the traffic accident between the bicycle, which drives into the motor vehicle lane, and the motor vehicle with a high speed will sharply increase, and the risk of the traffic potential danger of the mixed traffic flow when the motor vehicle density is low, is higher than the case when the motor vehicle density is high.