Measuring the Success of Transit-Oriented Development: Retail Market Dynamics and Other Key Determinants
Transit-oriented development (TOD) has become the dominant urban growth planning paradigm in the United States. Yet scant evidence has been proffered to indicate that it will produce significant environmental and social benefits commensurate with the costs of the major transportation system improvements that it requires.
Sixteen distinct planning issues will determine whether TOD significantly changes travel behavior in a metropolitan region. While some analysis exists, understanding of these issues needs improvement. In particular, more research is needed on non-work travel, retail market dynamics, and the likely constraints this $2.3 trillion area of business and human behavior imposes on TOD.
Over the past two decades numerous metropolitan areas in the United States have embraced the concept of transit-oriented development (TOD) in an attempt to control and manage the negative environmental and social impacts of dispersed growth patterns (Porter 1997). TOD, it is suggested, will increase pedestrian and transit trip taking while reducing the number and length of auto trips, and it will contribute to the livability that some feel is lacking in modern suburban development (Calthorpe 1993).
In essence, TOD means the creation of denser, mixed use activity nodes connected by high quality public transportation. Proponents believe that a combination of design features will induce travel mode shifts that result in reduced area-wide traffic congestion and improved air quality. These features include improved street connectivity, public amenities, and a concentration of residences and jobs in proximity to transit stations and commercial businesses. As an additional benefit, the enhanced pedestrian environment will increase "casual encounters" among neighbors that can contribute to a sense of community.
These efforts typically begin implementation with major new "mass" transit investments, often light-rail systems, that are designed to link central city cores, suburban downtowns, and other major activity centers. TOD is possible without new transit, but most metro areas choose to make the transit investment. Bernick and Cervero (1996) suggest that what is needed for TOD to succeed is a "transit metropolis," meaning a sufficient number of TODs having balanced or special uses that are connected and allow for efficient rail travel with bi-directional travel flows.
Construction of the new transit system usually precedes the land use restructuring required to effectively support the investment, i.e., the concentrations of population, employment, public amenities, and commercial activities that will attract transit riders in sufficient numbers to satisfy the transit system’s fare box recovery requirements. Commercial activities, in particular, often become a consideration after the transit system alignment is finalized and station areas are identified.
A useful review of previous studies in the urban planning and transportation literature of the transportation impacts of neo-traditional development and TOD is provided by Berman (1996). This paper summarizes several more recent empirical and modeling studies of TOD, and it indicates how TOD success should be measured. Specifically, it outlines the key factors that need to be understood and weighed before significant new transit investments are made. Our aim is to enhance the regional planning process in a way that leads to cost-effective investments of scarce public dollars.