Transportation Cost Index as a Performance Measure for Transportation and Land Use Systems: New Approaches and Application in Portland, OR

Recent U.S. federal and state laws are placing increasing emphasis on using comprehensive transportation performance measures to guide transportation decision making processes covering policy areas ranging from mobility, safety, economy, livability, equity, to environment. While it is relatively easy to build consensus on mobility measures that center on the transportation system alone, it is much harder for performance measures to incorporate both land use and transportation systems, loosely defined as accessibility measures, even with continuous efforts to catalog and design such measures (Zietsman, et al, 2011). Transportation Cost Index (TCI) for land use and transportation systems is a performance measure that fills important gaps in popular accessibility measures. Inspired by the Consumer Price Index (CPI), TCI is designed to be a measure of accessibility covering policy areas including equity and quality of life. This paper builds on earlier work on TCI and proposes two additional approaches to derive TCI. The authors test the approaches with data from the Portland, OR metropolitan area and conclude with an assessment of the TCI measure and a description of ongoing and future work.