针对上坡路段汽车需减小车速增大牵引力的现象,假定坡道倾度与车辆在坡道上的最大速度成反比,基于元胞自动机NaSch交通流模型建立包含有坡道的单车道元胞自动机模型,用数值模拟研究在周期边界条件下,坡道长度和倾度对交通流能耗的影响.结果表明:坡道长度和倾度对交通流能耗均有很大的影响,坡道长度越长、坡度越大,车速被限速越厉害,越容易产生交通拥堵,形成稳定的低速车流,因而对应的能耗值较小,所以尽可能地减少坡道的倾度和长度可以提高道路的通行能力.
The slope inclination is assumed to be inverse proportional to the maximum velocity from the phenomena that the vehicles must reduce the speed in order to increase the drag force in the up-slope section.Based on NaSch model,a cellular automaton model of slope for single-lane is proposed.The energy dissipation is investigated by numerical simulation with different up-slope length and up-slope inclination under the periodic boundary condition.The result delineates that the energy dissipation is significantly affected by up-slope length and inclination.The longer up-slope and the greater up-slope inclination,the greater speed limit is.Traffic jams and low-speed traffic flow are form and the corresponding energy dissipation value is small.So the capacity of road can be enhanced by reducing up-slope length and up-slope inclination.