Effects Of Left-turn Waiting Areas On Signal Timing And Traffic Emissions

In order to ease urban congestion,the addition of left-turn waiting areas at the intersections has become a method used by major cities to compete.However,the addition of left-turn waiting areas will inevitably increase the number of vehicle stops and affect vehicle emissions at the intersection.Explore the setup principle of the left-turn area,and find the optimal timing method.It is the subject of this paper to analyze whether the intersections need to set left-turn waiting areas to be considered at the analysis intersection.Based on the vehicle queuing theory,this paper analyzes the impact of adding left-turn waiting area to the intersection left-turning vehicle parking,delay,etc.On the basis of considering the short lane,the critical conditions for setting left-turn waiting areas are analyzed.A new signal timing optimization model was established with the objective of minimizing delays and emissions.Based on the calculation of emissions from motor vehicle specific power,quantitative analysis was conducted to determine whether the intersection is suitable for adding left-turn waiting areas.The full text is divided into four parts.The first part summarizes the research status of left-turn waiting areas and vehicle emissions by scholars at home and abroad,and introduces the research objectives and content of the paper.The second part combines the left-turning vehicle queuing theory and elaborates the critical conditions for the setting of left-turn waiting areas.The third part establishes a dual-objective optimization model that considers vehicle emissions and delays by obtaining the operating conditions of the vehicles in the left-turn waiting area.The fourth part takes the intersection of Wuyi Road and Southwest Road in Dalian City as an example to analyze the performance indicators such as the emissions,delays,and the number of stoppages of vehicles after adding left-turn waiting areas under different flows.The sensitivity of the left-turn area to slope change was analyzed based on the case of data,and the change of each performance index of the vehicle when there was additional left-turn waiting areas was analyzed at different slopes.The results reveal that the formulated model in this paper is applicable for signal timing optimization at intersections with left-turn waiting areas,and the settings of left-turn waiting areas make not only number of stops and delay but also traffic emissions increase.The waiting areas is sensitive to changes in gradient,and traffic emissions will increase as the gradient increases.Therefore,it is necessary to determine whether there is an additional need to add a left-turn waiting areas at the intersection after careful consideration.