Timetable Optimization Of Regional Bus Based On Node Importance

In recent years,it can be found that the long waiting and transferring time has become one of the important factors leading to low satisfaction from the satisfaction degree survey results of public transit.With the rapid development of vehicle road coordination technology,it is possible to carry out the coordinated transfer allocation of public transport vehicles between different lines.By identifying the key transferring stations of the regional public transport network,and adjusting the departure time of each bus by controlling the speed and vehicle trajectory,bus vehicles on different lines in the region can coordinated arrival at key transfer stations,which can reduce passenger transfer time and improve passenger’s experience.Therefore,in the environment of vehicle road coordination,it is of great theoretical value and practical significance to explore the mechanism of bus collaborative transfer and carry out the research on bus timetable optimization based on the importance of transfer stations.Firstly,the mechanism of bus coordinated transfer and the optimization strategy of regional bus timetable in the vehicle road coordination environment were discussed.Considering the constraints such as node importance,the deviation between the optimized and the original timetable,departure interval and so on,the point-by-point optimization strategy considering node importance and considering speed guidance area are formulated respectively;By comparing and analyzing the characteristics of bus data,this paper puts forward the analysis method of bus transfer passenger flow distribution characteristics and bus operation characteristics based on IC card data.Then,considering the contribution of bus stations to urban public transport network transportation,two primary indicators of topological network structure and node function and four secondary indicators such as node intermediary number and exchange passenger flow were selected to construct the node importance index system of transfer stations.The comprehensive weighting method combining information entropy method and expert scoring method was used to quantify the node importance.Then,it is proposed that the waiting time cost of non-transfer passengers,the waiting time cost of transfer passengers and the schedule deviation cost constitute the total cost of the system.Taking the total system cost as the goal,the regional bus schedule optimization model considering the node importance optimization strategy was constructed,and the medium and low passenger flow density routes in Daxing District of Beijing were selected as two examples.Compared with the effect before optimization,the total system cost with medium passenger flow density route decreases by 7.2%,and the total waiting time of non-transfer passengers and transfer passengers decreases by 11.4% and 6.5% respectively.The total system cost after and before the optimization of low passenger flow density route is reduced by 10.1%,and the average waiting time of non-transfer passengers and transfer passengers is reduced by 13.2% and 16.8% respectively.In general,the optimization effect of low passenger flow route is better.Aiming at minimizing the waiting time of passengers(non-transfer passengers and transfer passengers),a regional bus timetable optimization model considering speed guidance area was constructed,and a particle swarm optimization algorithm was designed.Finally,taking a regional bus route in Daxing District of Beijing as an example,this paper further discussed the optimization effect of the model under different speed guidance area and travel speed adjustment range.The results show that when the travel speed adjustment range is 10 km / h-60km/h,and the speed guidance area ranges from the up and down stops of the transfer station,the minimum average waiting time of non-transfer passengers is 5.12 min,which is 16.0% lower than that before optimization.when the range of travel speed adjustment is fixed,the longer the range of speed guidance area is,the smaller the waiting time of non-transfer passenger is.When the travel speed adjustment range is 25 km / h-40 km / h and the speed guidance area ranges from the up and down stops of the transfer station,the minimum total waiting time of non-transfer passengers is 1463.2min,which is 9.9% lower than that before optimization.The smaller the range of speed guidance area is,the shorter the waiting time for transfer is under the larger range of travel speed adjustment.The research results have certain significance for the compilation of regional bus timetable and the identification of key stations in the region.