The Research On Calibration Of Mixed Traffic Flow Model And Traffic Impedance Function

The problem of urban traffic congestion has played a significant role in block of moden economy growth and the traffic accident along with conjestion has a miserable impact on many perspectives of people’s lives. In order to implicate the rules of traffic flows and solve the catastrophic problem, groups of scholars have devoted themselves to the study of traffic flow theory. In China, the urban traffic flows contains not only the motorized flows but also the non-motorized flows, which has contributed to urban traffic conjestion. Thus, numerous experts in traffic and transportation study in the field of mixed traffic flows so that the theoretical foundation can be lay to solve the mixed traffic problem in China.The bus station set in the lane for non-motorized vehicles is one of the typical bottleneck in City Road Traffic System. The traffic bottleneck can not only form various types of congestion, but also induce many complex traffic flow phenomenon. In view of the urban road near bus stations, this article established a mixed traffic flow model simulating the interference betweem motorized vehicles and non-motorized vehicles near the bus stop and analyzed the bottleneck effect of the bus station.First of all, through empirical survey method, we obtained emperical data of the road near the bus station, and analyzed the measured road traffic data. We have concluded the relationship between velocity, flow rate and the road density. Furthermore, we concluded lane-changing rules of different kinds of vehicles from the video.Based on the random deccelerate cellular automaton model(VDR model) and multi-valued cellular automaton model(BCA model), we have estabished the mixed traffic flow model with periodic boundary condition for the urban road near the bus stop and analyzed the traffic flow, average speed along with space occupancy.The results show that the interference between motorized vehicles and non-motorized vehicles became more and more serious with the space occupied rate increase, but in a certain range it remained stable.Finally on the base of the established mixed traffic flow model along with the empirical data, we put forward a function of relationship between velocity and space occupancy. Then deduct the road impedence function at the certain circumstance.