Analysis of Transit Quality of Service and Employment Accessibility for the Greater Chicago, Illinois, Region

Abstract

A variety of transit decision support tools have been developed in the Chicago, Illinois, metropolitan area in recent years, including the Regional Transportation Asset Management System of the Regional Transit Authority and the Spatial Decision Support System of the Urban Transportation Center at the University of Illinois at Chicago. Although the Chicago metropolitan area has a variety of public transportation services, the quality of service available in an area and the extent to which transit allows area residents to access employment opportunities spread out across the six-county region vary substantially. This paper focuses on a spatial analysis of the variations of local transit service quality indicators as well as a composite regional employment accessibility measure. It explores the quality of the transit system in the Chicago region through a set of supply- and demand-side indicators at the census tract level. The supply-side indicators include a composite index of transit availability and frequency and transit station asset information. The demand-side measures include the computation of the regional employment accessibility index using a gravity model and transit travel times from travel demand models. A series of these indicators is mapped over the Chicago region at the census tract level. The paper also ranks census tracts on the local transit measures, as well as on the regional transit-based employment accessibility measures, and identifies those areas that are well off and worst off in regard to both types of indexes. The paper draws policy conclusions emanating from each of these categories.