Influence of urban road layout form on the traffic efficiency of the road network

In order to explore the influence of road layout form on the traffic efficiency of the road network, and implement the road layout concept of "narrow road and dense road network" better and faster, the "long side coefficient" of the road network is proposed to represent the length and width of the block enclosed by the road network. Based on the three dimensions of quickness, smoothness and "kinetic energy" of road network traffic operation, a comprehensive evaluation method of road network traffic efficiency including three indicators of road network average speed, road network parking times and road network traffic "kinetic energy" was established. In the case of keeping the road network density and occupied area unchanged, six road network scenarios under different long-side coefficients and traffic organization conditions were established based on Synchro. The simulation results show that the one-way traffic organization can significantly improve the traffic efficiency of the road network; increasing the "long side coefficient" of the road network can improve the average speed of the road network, reduce the number of stops and increase the maximum value of the "kinetic energy" of the road network; with the increase of traffic volume, the average speed of the road network decreases , which roughly drops to around 2/3 of the maximum average speed of the road network, and the "kinetic energy" of the road network reaches a maximum value. This study can provide theoretical support and experience for the layout of the narrow road network in the urban CBD and the improvement of the microcirculation of the road network organization in the historic districts, and promote the road network to give full play to the traffic operation efficiency under the constraints of limited space resources.