Improving Capacity Planning for Demand-Responsive Paratransit Services
Diwakar Gupta, Hao-Wei Chen, Lisa Miller, Fajarrani Surya
Report no. MnDOT 2008-09
This report proposes and evaluates two ideas for improving efficiency and service quality of paratransit operations. For carrying out this analysis, the authors use data from Metro Mobility, the agency responsible for providing ADA-mandated transportation services in the Twin Cities. However, the underlying principles, mathematical models, and algorithms are applicable to a variety of similar transportation operations in urban and rural areas.
The first idea is to re-optimize routes developed by Metro Mobility's route-building software (a commercial product named Trapeze) at the end of each day of booking operations to reduce the total time it takes to serve booked trips. The second idea evaluates the selective use of non-dedicated vehicles and service providers (e.g. taxi services) for lowering operational costs. Mathematical models and computer algorithms are developed for each of these approaches. These are then tested on actual operational data obtained from Metro Mobility.
The report shows that a conservative estimate of savings from re-optimization would be 5% of Metro Mobility's operating costs. Additional savings from the use of taxi service would be in the hundreds of dollars per day. The actual magnitude of these savings would depend on the proportion of customers who agree to travel by taxi.