关键词: 交通工程, 快速路, 紧急疏散, 匝道控制, 地面辅路

Abstract:

In view of the sharply increased demand during emergency evacuation, we propose using the ground bypass to buffer partial evacuating vehicles so as to lower the whole temporal and spatial risk of freeway evacuation system. Evacuating traffic evolution equations are constructed based on the macroscopic traffic flow model. In the equations, the impact of speeds of vehicles at on-ramps on the mainline traffic is clarified. This realizes the consistency of network state evolution in the macroscopic traffic flow model. In view of the dichotomy of travel time of the ground bypass consisted of an off-ramp, the parallel street road and an on- ramp, the discrete traffic flow evolution equations are constructed for the ground bypass. The above system equations can not only describe the main features of the traffic flow on the ground bypass, but also be seamlessly incorporated in the freeway state evolution system. The numerical analysis demonstrates that using the ramp metering and flow splitting to ground bypass, we can realize the minimization of the evacuation risk of the whole system.

Key words: traffic engineering, freeway, emergency evacuation, ramp metering, ground bypass