An insertion heuristic for scheduling Mobility Allowance Shuttle Transit (MAST) services

In this paper, we develop an insertion heuristic for scheduling Mobility Allowance Shuttle Transit (MAST) services, an innovative concept that merges the flexibility of Demand Responsive Transit (DRT) systems with the low cost operability of fixed-route systems. A MAST system allows vehicles to deviate from the fixed path so that customers within a service area may be picked up or dropped off at their desired locations. Such a service already exists in Los Angeles County, where MTA Line 646 is a MAST nighttime service, transporting passengers between a business area and a nearby bus terminal. Since the current demand is very low, the service is entirely manageable by the bus operator, but a higher demand would certainly require the development of a scheduling algorithm. The proposed insertion heuristic makes use of control parameters, which properly regulate the consumption of the slack time. A set of simulations performed in the service area covered by the existing MTA Line 646 at different demand levels attests the effectiveness of the algorithm by comparing its performance versus a first-come/first-serve (FCFS) policy and optimal solutions generated by a commercial integer program solver. The results show that our approach can be used as an effective method to automate scheduling of this line and other services similar to it.