Research Article

An Optimization Strategy for Truncating Ultralong Bus Lines Integrated with Metro Networks

Table 1

Notations.

NotationsDefinitions

Sets
Set of passengers,
Set of buses,
Set of bus stops on the bus line,
Set of bus types, , representing the vehicle type, where represents small bus and represents a larger bus
Set of bus lines,
Set of metro lines,
Set of passengers who choose to transfer to the metro at the truncation stop
Set of passengers who choose to transfer to the bus at the truncation stop
Parameters
Length of the original bus line (km)
Length of new bus line (km)
Average distance between bus stops (km)
Average distance between metro stops (km)
Theoretical maximum length of urban bus lines (km)
The average speed of buses on a metro line (km/h)
The average maximum travel time of 95% of the residents (minutes)
The average speed of trains on a metro line (km/h)

NotationsDefinitions

The average travel speed of bus (km/h)
Constant, passenger waiting time penalty critical value (minutes)
Constant, maximum number of transfers for passengers
Constant, maximum waiting time for passengers, (minutes)
Constant, maximum and minimum headway of vehicles (minutes)
The probability of passenger transferring to bus at truncation stop ,
Bus ride time for passenger (minutes)
Average wait time at bus stop for passenger (minutes)
Metro ride time for passenger (minutes)
Average wait time at metro stop for passenger (minutes)
Crowding penalty coefficient (CNY/stop)
Passenger transfer penalty coefficient (CNY/person)
Value of time (CNY/h)
The penalty factor when waiting time is longer than (CNY/person)
Coefficient of crowding
The number of buses of type at line
Vehicle type operating cost per kilometer (CNY/km)
The ticket cost of riding the type bus (CNY/person)
The ticket cost of passenger when riding the metro (CNY/person)
The purchase cost of a single bus with vehicle type that is averaged to each day based on its service life (CNY/vehicle)
The salary of a single driver for bus type (CNY/person)
The total number of passengers in the original line
The maximum passenger capacity for bus type (person)
The headway of metro line (minutes)
The total number of stops in the original bus line
Minimum and maximum truncation stop limits
Transfer time for passenger at stop (minutes)
The maximum number of buses of type required in line
Auxiliary variables
Total operating cost of buses (CNY)
Total ticket cost for passengers (CNY)
Total time cost of passenger travel (CNY)
Total fixed cost of the bus company (CNY)
Penalized total cost (CNY)
Total travel cost of passengers (CNY)
Total cost of the bus company (CNY)
The number of passengers in bus at stop (person)

NotationsDefinitions

Number of total passengers in an hour of line (person/h)
The total number of passengers transferring at stop (person)
The total number of passengers transferring to bus at the truncation stop (person)
The total number of passengers who transferring to metro at the truncation stop (person)
Binary variable, 1 if passenger passes through stop , and 0 otherwise
Binary variable, 1 if passenger chooses vehicle at the stop , and 0 otherwise
Binary variable, 1 if passenger in-vehicle alights at stop , and 0 otherwise
Binary variable, 1 if passenger chooses metro line , and 0 otherwise
Decision variables
The bus headway of line (minutes)
Binary variable, 1 if is the truncation stop, and 0 otherwise
Binary variable, 1 if the waiting time of passenger is greater than , and 0 otherwise
Binary variable, 1 if the number of passengers in-vehicle exceeds at stop , and 0 otherwise
Binary variable, 1 if existing at least a metro stop near bus stop , and 0 otherwise
Binary variable, 1 if the vehicle of type is in the line , and 0 otherwise