自由流速度变化下快速路路网性能变化研究

Network performance research of expressway when free-flow speed changes

在经典元胞传输模型的基础上,采用上下匝道无控制策略构建快速路元胞传输模型。依据模型算法对城市快速路进行仿真,分析广义路网容量和狭义路网容量与系统总延误之间的关系。仿真结果表明:在自由流速度逐渐增大情况下,城市快速路总延误先减小后增大,而广义路网容和狭义路网容量都是先增大后减小,总延误谷值与路网容量峰值相对应。确定该结论在一定条件下与城市快速路越快越堵悖论具有一致性。

Based on the classical cell transmission model, this paper constructs the cell transmission model about express-way by not controlling the up-ramp and down-ramp. And this paper goes on the simulation of urban expressway on the basis of the model algorithm and analyzes the relationship between the generalized road network capacity or narrow road net-work capacity and total system delay. The simulation result shows that urban expressway delay decreases first and then increases, while the generalized road network capacity and the narrow road network capacity first increase and then decrease as the free-flow speed increases. The minimum delay value corresponds with the peak of the road network capacity. The result also shows that it has the same aspects with the faster the more congestion in urban expressway in certain conditions.