Have TOD promoters been putting the cart before the horse?

Building on its previous publication, Transit and Employment (2008), the Center for Transit-Oriented Development recently released a new report, Transit-Oriented Development (TOD) and Employment. The report challenges the assumption that employment dispersal outside of central business districts necessarily leads to sprawling, auto-centric communities and makes the case for molding existing employment clusters into TODs rather than building TODs from the ground up as mixed-use developments consisting primarily of housing and retail establishments.
Most TOD studies have focused on the residential end of the commute trip. However, because concentrated employment is more closely associated with transit usage than is residential density, improving transit and diversifying the land use mix at existing employment clusters may be a more effective way of creating TODs.
Connecting the largest and most concentrated regional employment centers via transit “spines,” with feeder services connecting to other commercial and residential areas, sets the stage for increased employment and residential density and fuller transit use.
In addition to creating transit links between employment clusters, the use of placemaking strategies is another critical element for effective TODs. Even with transit service, workers in areas dominated by stand-alone office buildings often do not use transit because of the risk of being stranded and unable to run errands during the midday. By limiting parking, increasing density, and encouraging residential and retail development, these employment clusters can be transformed into viable, transit-friendly, mixed-use nodes.
The trend towards employment dispersal away from central business districts does not necessarily have to be reversed in order to create sustainable cities. With improved transit service and good planning strategies, these dispersed employment clusters can form the basis of successful transit oriented developments. On the other hand, building mixed-use residential/retail TODs before ensuring that the available transit services provide access to major employment clusters may be a losing strategy.