Effects of Light Rail Transit in Portland: Implications for Transit-Oriented Development Design Concepts

In the Portland, Oregon, region many local planners have embraced the neotraditional planning concept in the form of transit-oriented development (TOD). One of the primary components of transit-oriented development, light rail transit (LRT), has been in place in Portland long enough to provide data for analysis. Because neotraditional planners often emphasize LRT as a crucial element in decreasing auto use and in encouraging high-density development, this paper examines the effects of LRT in the Portland region including mode share, density, and property values. The empirical analysis provides evidence that light rail alone has not been sufficient to have an appreciable impact on development patterns, residential density, auto ownership, and transit modal behavior, although there has been some positive effect of rail on single-family property values. There has also been less of a decline in transit use and slower growth in two-car households in the LRT corridor as compared to a parallel bus corridor. The small positive effects of LRT may indicate the beginning of a self-selection in housing location choice wherein persons desiring rail transit choose to live where it is available. This assessment of the evidence in terms of impacts on development trends indicates the extent to which consumer preferences have responded to LRT investments. This kind of assessment is needed to provide the basis for estimating travel mode shares and market shares for dispersed and concentrated development forms. Examination of data suggests that it may be advisable for planners to entertain more modest expectations of LRT.