Accessibility-based transit planning

Abstract

A method for evaluating transit planning proposals using accessibility metrics is advanced in this research. A transit-accessibility model is developed intended for use by in-house transit agency planning staff as a preliminary project design and evaluation tool. It relies on readily available socioeconomic and travel data and a GIS-supported representation of the transit network. It is intended to inform planning decisions using transparent and intuitive models in a less time consuming and expensive manner than more elaborate and comprehensive planning methods. Emphasis is placed on the visualization of changes in transit level of service resulting from major facility investments. In this capacity, the accessibility metric can assist in identifying the potential ridership change and development impacts of a project. The accessibility model relies on the travel-time outputs of a transit network model, socio-economic data and information on current travel patterns. Development of a network model of transit service in the Chicago region with a focus on CTA bus and rapid transit and METRA commuter rail service is documented. The network model is intended to support on-going research, beyond the scope of this thesis, as part of the collaborative Chicago Transit Authority-MIT research effort. The impact of the proposed Circle Line rail project on employment access and commercial development potential is analyzed to illustrate the potential of the accessibility metric. The model is also applied as a sketch planning tool for intermediate stations on proposed Airport Express trains between downtown Chicago and its two major airports.

(cont.) Findings suggest that much of the improvements in employment access from the Circle Line occur in early project phases, there is strong potential for increased commercial development in the corridor, and some improvement in regional transit connectivity. The Airport Express train could substantially improve airport accessibility with the addition of an intermediate station on the O'Hare branch.