Methodology to optimize resource requirements of a demand responsive transport system for persons with disabilities: a case study of Flanders

Abstract

Demand responsive transport (DRT) services are frequently offered in the context of door-to-door transportation of elderly and persons with disabilities. The present study describes an optimization methodology to analyze the minimal resource requirements of a DRT system in terms of vehicles and drivers required and total distance traveled, by means of a vehicle routing plan, taking into account heterogeneous users (persons with different severity and type of disabilities), heterogeneous vehicles (regular and wheelchair adapted vehicles) and multiple geographically distributed depots (locations where vehicles are stored). The implementation of a geographically covered DRT system for the transportation of persons with disabilities in Flanders in the prediction years 2015, 2020 and 2030, was applied. A microscopic simulation of the demand of persons with disabilities for transportation, spatial and temporal effects taken into account, was applied over the whole service area, in order to obtain a detailed overview of all transportation requests that need to be processed by each individual service provider. Specific travel data of persons with disabilities (with specific disability-related attributes) were collected by means of a survey that was distributed among 344 persons with disabilities. Next, a separate vehicle routing plan was created for each service provider for both a weekday and weekend day, resulting in the required number of vehicles and vehicle kilometers. The results of the Flemish application show that the new DRT system seems unaffordable for the society, despite the applied optimization methodology