关键词: 小汽车-卡车异质交通流, 坡道, 元胞自动机, 安全距离

Abstract: To better understand the characteristics of traffic flow mixed by the cars and trucks on an up-slope, a cellular automata-based traffic flow model is proposed for single lane traffic considering the safe driving rules. The study reveals some new findings. Firstly, if a slope exits on a flat road, the traffic flow characteristics will change significantly. The previous decentralized congestion zone is changed for much short-intensive congestion, and focused on the slope and slope front. The slope impacts on traffic congestion significantly. A 40 m-long slope will increase nearly 10% increase congestion. Secondly, the trucks in the traffic flow can ease congestion in the low density case; however, the trucks’ impact on congestion is limited and even can be ignored for the high density case. Thirdly, no matter what the density and slope length are or whether a truck exists, the traffic congestion increases with the increment of the slope gradient, which indicates that reducing slope gradient can reduce traffic congestion. In addition, when the slope gradient is fixed, increasing slope length can also reduce traffic congestion.

Key words: car-truck heterogeneous traffic flow, slope, cellular automata, safe distance