Multiobjective Optimization Model for Prioritizing Transit Stops for ADA Improvements

Inaccessible transit stops prevent people with disabilities from using fixed-route transit services, thereby limiting their mobility. The Americans with Disabilities Act (ADA) prescribes the minimum accessibility requirements for transit stops for riders with disabilities. In addition, transit agencies may also choose to implement the "universal-design" paradigm, which involves higher design standards than current ADA requirements and includes amenities that are useful for all riders, such as shelters and lighting. Because of budget limitations, however, transit agencies can select only a limited number of transit stops for ADA improvements each year. To increase the impact of these improvements, it is desirable that transit stops be selected such that they will maximize the overall benefits to patrons with disabilities. This paper describes a multiobjective binary nonlinear programming model for selecting, within a limited annual budget, a priority set of transit stops for improvements. The model aims to achieve two objectives, namely, meeting the minimum ADA standards and the universal-design standards. Compared with the traditional approach of selecting stops for improvements, which are often based on either staff experience or requests from elected officials, the optimization approach described in this paper provides a more objective platform to identify better candidate stops for ADA improvements. DOI: 10.1061/(ASCE)TE.1943-5436.0000244. (C) 2011 American Society of Civil Engineers.