Optimizing dial-a-ride services in Maryland: Benefits of computerized routing and scheduling

This paper reports on a system developed to address the dial-a-ride problem and an implementation for Maryland where real-world practical constraints are considered in providing customized vehicle routing and scheduling for about 450 trip requests daily. The system, called Mobile Resource Management System (MRMS), allows for dispatch operators to quickly study different operational scenarios and, in a strategic setting, explore tradeoffs between level-of-service and various system characteristics, including fleet composition, fleet size and dispatch rules. Such insights play a key role in making long-term investment decisions or estimating cost of servicing contracts that have service level agreements. Test comparison of manual and MRMS-based routes indicated an estimated annual operational expense reduction of $0.82 million, or about 18% of the total annual expense. In addition to the cost benefits, improved quality of service and the reduction in total vehicle-kilometers traveled leading to environmental benefits are demonstrated.