NSF/USDOT: Innovative Feeder Transit Services: Mobility Allowance Shuttle Transit - MAST

University Of Southern California, Los Angeles CA

Investigators

Abstract

Demands on urban transit agencies for improved and extended services are increasing; yet, there is little public support for increases in fares or subsidies. Therefore, transit agencies are currently seeking ways to improve service flexibility in a cost-efficient manner. Traditional fixed-route bus transit systems are cost effective; however, the general public considers the service to be inconvenient because of a lack of flexibility. Demand Responsive Transit (DRT) networks are flexible, but tend to be much more costly to deploy than fixed-route systems. To overcome these limitations, the PIs will explore and develop an innovative concept called Mobility Allowance Shuttle Transit (MAST) that merges the flexibility of DRT systems with the low cost operability of fixed-route bus systems. A MAST service has a fixed, base route that covers a specific geographic zone. The innovative twist is that MAST allows buses to deviate from the fixed path so that passengers wanting service in the vicinity of the path may be picked up or dropped off at their desired locations. Passengers contact the dispatch center to request a pick-up and receive service from the next available bus. The only restriction on flexibility is that the deviations must lie within a predetermined distance from the fixed, base route. The PIs' research objective is to recommend a viable MAST architecture, specifically providing (1) the route deviation distance, (2) the schedule slack time, and (3) the policies for real-time sequencing and assignment of pick-ups. This research will produce a regression-based demand model and a nonlinear dynamic bus headway distribution model. These models will be used to drive the design process as well as to synthesize operating policies. The approach will be validated through an extensive simulation study. This research will determine the demand and operating conditions that will allow MAST to be financially viable. The successful implementation of MAST will improve the desirability of transit as an alternative to private automobiles, and could result in increased transit ridership. An increase in transit ridership would likely lead to reduced roadway congestion and improved environmental conditions, such as reductions in greenhouse gas emissions.