# Research on Optimization of Multi-Objective Regional Public Transportation Scheduling
## 2 Literature Review  
Compared with single-line public transportation dispatching, regional public transportation dispatching can make public resources more fully utilized [4, 5]. Transfer is the main factor of regional public transportation scheduling, and synchronous optimization of regional public transportation timetable can improve the transfer efficiency. Therefore, some researchers have studied the problem of synchronous transfer of regional public transportation scheduling. [PERSON] and [PERSON] [6] considered the bus timetable affected by running late to achieve the optimization of departure interval and fleet size. [PERSON] and [PERSON] [7] established a bilevel programming model between the timetable generation andvehicle scheduling in the bus scheduling system according to the regional public transport scheduling mode. [PERSON], [PERSON] and [PERSON] [8] established a collaborative optimization model to maximize the number of buses arriving at the station synchronously in the region. [PERSON] and [PERSON] [9] optimized the departure schedule under the determination of the synchronous transfer time window to maximize the synchronous number. [PERSON] [10] considered the problem of developing synchronized timetables for bus transit systems with fixed routes to have maximum number of simultaneous arrivals. [PERSON], [PERSON], and [PERSON] [11] optimized the departure schedule based on the shortest waiting time of passengers and the maximum number of bus berths. [PERSON] et al. [12] evaluated the degree of synchronous bus arrival by defining the synergetic coefficient. [PERSON] and [PERSON] [13] took the total travel time as the target and adopts the synchronous transfer problem of buses under different strategies. [PERSON], [PERSON] and [PERSON] [14] realized synchronous transfer between urban bus lines and rural bus lines by optimizing the vehicle arrival time of transfer routes. [PERSON] et al. [15] presented a model to optimize the bus scheduling by taking into consideration of both bus stop and route segments of the city. Taking into account congestion on the public transport system and works by considering elastic demand, [PERSON] et al. [16] proposed an optimization model for designing the intervals and sizes of buses circulating on public transport networks by minimizing the system's operating and user costs. [PERSON] et al. [17] built an optimal model to schedule the departure time of each bus service with the objective of minimizing the average waiting time. [PERSON], [PERSON] and [PERSON] [18] dealt with the flexible vehicle and crew scheduling problem faced by urban bus transport agencies. [PERSON], [PERSON] and [PERSON] [19] proposed a demand and travel time responsive model to maximize the benefit of the operator by preparing an optimal schedule. [PERSON], [PERSON] and [PERSON] [20] developed three explicit integer linear programming models to formulate: the bus driver scheduling, bus and driver scheduling, and bus and driver scheduling with mealtime windows, respectively. [PERSON] et al. [21], [PERSON] et al. [22; 23], [PERSON] et al. [24] formulated some multi-objective capacity models to deal with transportation planning problem. A review of the literature on regional public transport scheduling reveals that the existing research mainly considers the constraints on the waiting time for passengers, system's operating cost or the degree of transfer synchronous. However, the losses of non-synchronized transfer passengers who choose to use alternative modes of transport because of the waiting and the bus capacity are rarely considered. The total waiting cost of passengers should include the waiting cost of passengers who have not achieved easy transfer and those who have to choose other modes of transportation, and the waiting time cost of non-transfer passengers. In terms of operating cost, departure frequency or full load rate are always considered. Effective operating time is also a major component of operating costs.