Search

Like many large US metropolitan areas, the San Francisco Bay Area has experienced rapid suburban employment growth since 1980, much of it concentrated in sub-centres. This paper shows that, contrary to the co-location hypothesis, employment decentralisation has not been associated with shorter average commute distances or durations in the Bay Area. Combining statistics on shifts in modal splits and average vehicle occupancy levels reveals that parallelling the region's sub-centring trend has been a substantial increase in average commute vehicle miles travelled (VMT) per employee between 1980 and 1990. The largest increases occurred in the fastest-growing and most remote suburban centres. Using decomposition analysis, we found that increasing commute distances contributed the most to rising commute VMT per employee, and the distance factor had proportionately the greatest effect on rising commute VMT rates in the most peripheral work centres. Since shifts in commute VMT per employee are thought to be strongly associated with transport externalities, we conclude that the social and environmental implications of the Bay Area's regional growth trends deserve more public policy attention than given to date. [ABSTRACT FROM AUTHOR]

Equity in access to opportunities is increasingly recognised as an essential component of sustainable development and transport. This study presents a spatial and temporal examination of commuting inequality between cars and public transit in the San Francisco Bay Area. Results visualised in the maps show considerable inequality and temporal changes in job accessibility and commuting time between cars and public transit as well as among locations within the metropolitan area. Results from OLS and spatial regression models indicate that, in both 1990 and 2000, greater job accessibility was significantly associated with shorter commuting time for driving alone as well as for public transit, but the degree of this association was considerably greater for public transit than for driving alone. Urban and transport development that enhances mobility and accessibility for public transit relative to cars should be strongly encouraged. [ABSTRACT FROM AUTHOR]