Analysis of traffic flow with micro-cars with respect to safety and environmental impact
Analysis of traffic flow with micro-cars with respect to safety and environmental impact
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DOI：
10.1016/j.tra.2019.03.013
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发表时间：
2019-06
期刊：
影响因子：
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通讯作者：
Ruifang Mu;Toshiyuki Yamamoto
中科院分区：
文献类型：
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作者：
Ruifang Mu;Toshiyuki Yamamoto
本研究分析了车辆组合中微型车存在时的交通流特征。建立了一种双车道多元胞交通自动机（TCA）模型，用于模拟由传统乘用车和微型车组成的混合交通流。模拟了长度为700 m的城市高速公路和主干道的两车道路段；后者包括在中点有一个信号周期的交叉口延迟。仿真研究了不同比例微型车的交通流。计算交通状况的四个方面：变道次数、减速次数、速度变化系数（这可能表明安全性能）以及HC、CO和nox排放（作为对环境影响的衡量标准）。仿真结果表明，微车混合流在高速公路和主干道上的变道频率都较高，但主干道上的增量变化较小。随着微型汽车在高速公路上的引入，在自由流中减速频率增加，在拥挤流中减速频率减少；然而，在主干道上，它降低了减速频率，对自由流的影响不显著。微型汽车的引入对速度变化系数也有类似的影响。在高速公路自由流动条件下，微型汽车的引入对上述三个与安全相关的参数有负面影响。然而，对于主干道上的自由流或高速公路和主干道上的拥挤流，由于微型汽车的影响在三个参数上是相互矛盾的，所以结果并不确定。机动车排放，如HC， CO和NOx，在高速公路上自由流动时增加，但在主干道上总是较低。
This study analyzes the characteristics of traffic flow in the presence of micro-cars in a vehicle mix. A two-lane multi-cell traffic cellular automaton (TCA) model is formulated to simulate mixed traffic flow comprising conventional passenger cars and micro-cars. The segments of an urban highway and arterial road, both with two lanes and measuring 700 m in length, are simulated; the latter includes an intersection delay with a signal cycle at the midpoint. Traffic flows with different proportions of micro-cars are investigated in the simulation. Four aspects of traffic conditions are calculated: the number of lane changes, the number of decelerations, the coefficient of speed variation (which may be indicative of safety performance), and the HC, CO, and NOxemissions (as a measure of environmental impact). The simulation results suggest that mixed flow with micro-cars leads to higher frequencies of lane-changing on both highways and arterial roads, although the incremental change on the latter is smaller. With the introduction of micro-cars on the highway, the frequency of decelerations increases in free flow and decreases in congested flow; however, on the arterial road, it decreases the frequency of decelerations and has an insignificant impact on free flow. The introduction of micro-cars has a similar impact on the coefficient of speed variation. Under free flow conditions on highways, the introduction of micro-cars has a negative influence on the three aforementioned parameters related to safety. However, for free flow on arterial roads or congested flow on highways and arterial roads, the results are inconclusive because the effect of micro-cars is contradictory in terms of the three parameters. Vehicle emissions, such as HC, CO, and NOx, increase during free flow on highways, but are always lower on arterial roads.