Spatial dimensions of workplaces and the effects on commuting: the dase of metropolitan Dallas-Fort Worth

摘要

There has been a lively debate over using land use strategies to reduce automobile dependence over the past decade. As a part of the issue, this study investigates the spatial characteristics around workplaces and their relationships to commuting made by the employees in metropolitan Dallas-Fort Worth. The tools of geographic information systems (GIS) are utilized to measure workplace environs. Several statistical methods are applied to analyze commuting behavior.This study finds that low-density suburban workplaces are associated with shorter vehicle travel times but more drive-alone trips. While major suburban centers attain some level of compact development in terms of local activity mix and regional accessibility, employees in these centers are far more automobile dependent than employees in older centers in the central city. In the suburban locations, workplaces in residence-based centers and master planned communities with a mix of activities are associated with less drive-alone commuting and more carpooling. Workers take advantage of the abundance of activities, as larger and denser centers are associated with more non-work activity stops after work. Yet, the trip chaining is overwhelmingly driven by automobile use.This study also finds that spatial factors are significant in explaining commuting behavior. Yet, the importance of spatial factors varies with the aspect of travel. Spatial factors do a better job in explaining travel times than in explaining travel mode and trip chaining. The way a particular spatial factor affects commuting also varies with the aspect of travel. For instance, land use intensity factors are associated with longer travel times but less drive-alone trips. While this study suggests that concerted planning may affect travel, some socioeconomic variables, including income and automobile ownership, are strongly related to more automobile travel. The findings suggest that the land use strategies to cope with transportation and air quality problems, such as new urbanism and jobs-housing balance, would be a viable option in and around employment locations. But, such strategies should be carefully designed because of the differences in effectiveness of spatial factors with travel outcomes and the trade-offs between travel outcomes with a particular spatial factor.