Multi-Line Trams Control Approach With Arterial Traffic Signal Coordination

The construction of trams in China is in the ascendant,but there are still certain deficiencies in the arterial traffic signal optimization with tram priority.On the one hand,in the existing research results,only social vehicles or only trams are considered.There are few studies considering both of them.On the other hand,there is no research on the green bands model of the multi-line trams sharing common track.In the process of network operation of trams,there will inevitably be operation mode of the multi-line trams sharing common track.Therefore,the research paper is organized as follows:By referring to the classic literature and relevant national regulations,the characteristics of tram are obtained,including the outline dimensions and driving parameters of trams.Then,we analyze the characteristics of road and intersection traffic organization of tram and design the matrix expression method of the tram laying mode at the intersection.For different types of the tram laying mode,a qualitative analysis of the conflict between the tram and the social vehicle is carried out.Finally,through the quantitative analysis of the conflict,the method of calculating the emptying time of tram at the intersection is obtained.Based on the characteristics of intersection traffic organization of the multi-line trams sharing common track,we analyze the conflicts of merging,diverging and cross.Combined with the line characteristics of the multi-line trams,we study the stop time,the interval of departure,the departure time,and the run chart of the tram,and obtain the calculation method of the departure interval and departure time of avoiding two or more trams arriving at the merging point in one cycle.Combined with the NEMA signal phase rule,the phase sequence designed method of the different types of the tram laying mode at intersection is obtained.Combining the advantages of the MAXBAND and MULTIBAND green wave models,abandoning the concept of inbound and outbound,we design a completely path-based multi-line tram green wave model,where the green wave bandwidth of the social vehicle path is variable but that of the tram path is fixed.The model includes constraints based on space-time graphs,signal control schemes,travel time,and green wave bandwidth of trams.The model aims to maximize the bandwidth of social vehicles based on weights coefficients.Then,the green wave of the social vehicle path and the tram path under the same signal control scheme could be abtained.Based on the green wave model,a signal control strategy based on the stop induction priority is further proposed.We design the loopless network of multi-line tram,signal timing parameters and vehicle path parameters,and by solving,the green wave model optimization results are obtained.Through SUMO micro-simulation software,the three schemes of the no green wave coordination,the basic green wave coordination,and the green wave coordination based on the stop induction priority is simulated.Then,we analyze the average queuing length and average queuing time of the intersections,the average parking times,average parking time,average travel time,average time loss of the tram paths and social vehicle paths.The results show that the multi-line tram arterial green wave coordination model proposed in this paper can improve the traffic efficiency of the trams and social vehicles based on the green wave path.At the same time,the efficiency of the operation of the road network is also improved.After the priority control of the stop induction,the efficiency of the opration of the tram can be further improved without affecting the social vehicle traffic efficiency.