In case of dynamic demand with an asymmetric load direction over a certain period of time, the sharing system operator might have to relocate vehicles during operation. This means they are moved from one station to another. When optimizing the number of relocated vehicles, the demand served, the costs of relocation and the avoidance of overcapacity compete with each other.
The aim is to achieve optimal station occupancy by relocating the vehicles. A limiting factor is the relocation rate [vehicles / time interval], but not the travel times, distances or any other costs. The continuous relocation process discretely influences the procedure at the end of each time slice. Relocation is performed for all transport systems simultaneously.
The procedure moves vehicles from stations with a surplus of vehicles to stations with a demand for vehicle. Stations with the most pressing demand are served first. These are generally stations with negative occupancy rate or an occupancy that lies above the capacity of the station. The procedure distinguishes between five station categories. These are based on the demand for vehicles and the availability of vehicles.
A) stations with a negative occupancy rate
B) stations with an occupancy below the optimal occupancy
C) stations with optimum occupancy / or stations without a predetermined optimum occupancy
D) stations with an occupancy above the optimum occupancy
E) stations with an occupancy above the capacity of the station
The procedure attempts to gradually move vehicles from stations of category E to stations of category A, until the upper threshold (vehicles moved) or lower threshold (vehicles received) of the next category is reached. If there are no more stations left in a category, the procedure continues with the following (A->B/E->D) category. The procedure ends if at least one of the following criteria is satisfied:
1. The maximum number of permissible relocations is reached.
2. All stations are category C.
3. The stations have one category and the same rating (vehicle shortage / demand)
The optionally available vehicle depot is used a source of vehicles or merely a place where vehicles are stored before they are moved to stations of the optimal category C.
The procedure described here is a simple approach to vehicle relocation. For example, there is no tracking of individual vehicles. This means network performance calculation that has to be performed by the operator does not take place. This also applies to route optimization during the relocation process.
