University of California Transportation Center
The Road Less Traveled: Land Use and Non-Work Travel Relationships in Portland, Oregon
- Author(s): Greenwald, Michael Joseph
- et al.
New Urbanism seeks to exploit a relationship between urban form and travel behavior in order to develop communities which are simultaneously more egalitarian, more pleasant, and less costly to society as a whole. The focus of New Urbanist design practices is to create environments (both urban and suburban) which promote walking and transit over private automobile use as a mode of travel. Specifically, New Urbanists contend higher residential density, closer residential proximity to employment and shopping, grid street patterns and greater access to transit will lead to reductions in automobile travel. This dissertation tests those assertions and discusses the resulting policy implications. The work presented here concentrates on transportation mode choice for non-work travel, defined here as all travel not related to employment or employment related activities. Non-work travel is of particular interest because it comprises a majority of activities involving travel, yet modeling strategies for various policy goals (e.g., clean air, traffic congestion, transit development) ignore non-work travel, in favor of analyzing employment related commute behavior.
The working hypothesis is that land use patterns consistent with New Urbanist principles can alter a person’s willingness to substitute other travel modes (i.e., walking and/or transit) for automobile use by way of changing the amount of time needed to complete trips by these other modes. This willingness to substitute then impacts the number of trips by each mode of travel observed for individuals. The results described here suggest New Urbanist land use practices can work as their proponents suggest, even when one accounts for the interference of people self-selecting into residential environments which promote one form of travel over others. These findings are tempered by further analysis suggesting New Urbanist designs must have their various elements properly balanced, or none of the proposed benefits will come to pass. Also, it appears that in the context of analyzing distances traveled and number of trips made, New Urbanist practices simply provide a premium on travel that can be completed close to the home. The impact of these findings on theories and policies tied to travel behavior are discussed in the concluding section.