Research Article

Integrated Optimization of Tram Schedule and Signal Priority at Intersections to Minimize Person Delay

Table 2

Notations and parameters.

General notations

Index of nodes, including stations and intersections
Index of intersections
Index of stations
Index of trams
Index of TSP actions, where green extension, phase insertion and early green are denoted as , , respectively
Index of approach lane direction, where through, left-turning and right-turning are denoted as z, l,r, respectively.

Tram parameters

Arrival time of tram m at node e based on the minimal travel time schedule
Departure time of tram m from node e based on the minimal travel time schedule
Minimum running time for each tram from node e to node e+1
Maximum running time for each tram from node e to node e+1
Minimum dwell time for each tram at station s
Maximum dwell time for each tram at station s
Minimum headway between two consecutive trams arrivals at the same station
Minimum headway between two consecutive trams departures at the same station
Minimum headway between a tram departure and another tram arrival at the same station
Load factor of tram m between two consecutive stations
Average load factor of tram m along the tramline
Fixed passenger occupancy of tram m
Weight factor determining tradeoff of person delay between tram and auto vehicles

Signal parameters

Index of signal cycle at intersection i
Index of phase in cycle k for intersection i
The phase serving tram, which is also called critical phase
1, if phase n is the critical phase N; 0, otherwise
1, if phase n is the previous phase before critical phase N; 0, otherwise
The unadjusted cycle length in cycle k at intersection i
The unadjusted green duration of lane group j during phase n in cycle k at intersection i
Green ratio of lane group j during phase n in cycle k at intersection i
Minimum green duration for TSP actions
Maximum green duration for TSP actions
Minimum red time between two green phases in a signal cycle
1, if a TSP action is taken in cycle k at intersection i; 0, otherwise

Traffic parameters

Average vehicle delay of lane group j during phase n in cycle k at intersection i
Average vehicle delay in cycle k at intersection i
Original traffic volume of lane group j during phase n in cycle k at intersection i
Variation of traffic volume caused by applying TSP strategy
Saturation of lane group j during phase n in cycle k at intersection i
Saturation volume of lane group j during phase n in cycle k at intersection i
Capacity of lane group j during phase n in cycle k at intersection i
1, if tram m arrives at intersection i during phase n in cycle k; 0, otherwise
Auto traffic volume of intersection i in cycle k
Passenger occupancy of an auto vehicle