Station-Area Housing and Employment Density
Studies in different metro areas have shown (Moudon et al 1997; Cervero & Kockelman 1997) that denser residential development within an easy walk of a TOD center and transit station will generate walk trips, and that these trips may substitute for vehicle trips. However, in the case of work trips, regional success is dependent on density at both trip origin and destination. At least a few concentrated employment centers served by transit are needed to attract significant numbers of commuters. The problem is that employment locations have become highly dispersed outside of the central business districts in most metro areas.
These trends appear to be continuing as central cities decline in relative, and some cases absolute, share of regional employment. For example, in 1970 39% of all jobs in the Seattle metro area (central Puget Sound region) were located in the central city. By 1994, just 29% of regional employment was inside the central city, even though it has remained a vibrant commercial center. Another 17% was situated in 16 satellite urban centers. More than half of all jobs were located in areas outside urban centers -- in commercial and industrial zones spread across four counties.
Cervero (1996), acknowLEDging the problem of density at both ends of the commute trip, cites the example of commuting in the San Francisco Bay area. Using 1
