The correlational and causal investigation into the land use-transportation relationships: evidence from the Dallas-Fort Worth metropolitan area

摘要

The role of land-use and related policies in reducing automobile dependence hasbeen the subject of heated policy debate for over two decades. Previous research hasshed light on the correlations between land-use and travel. Yet a crucial knowledge gapstill exists in establishing causality between the two. Do changes in land-usecharacteristics cause behavioral changes in individuals?????? decisions on what transportationmeans to use for travel? How does land-use as a contextual factor shape the decisionprocess and outcome of trip frequency and travel mode choice? These questions remainlargely unanswered.Attempting to fill the gap, this study applied the directed acyclic graphs methodto identify the causal relationship between land-use and travel in the 9-county Dallas-Fort Worth (D-FW) metropolitan area. The logit captivity (LC) model, an extension tothe conventional multinomial logit, was utilized to capture the contribution of land-usein affecting individuals?????? decisions on travel mode choice. All the data for this study were obtained from the North Central Texas Council of Governments (NCTCOG).Evidence from the D-FW region confirms to a certain extent the causal effects ofland-use on travel. For work trips, increases in regional accessibility, job density andshare of commercial land-use reduce the use of automobiles. Higher regionalaccessibility, however, causes households to generate automobile trips and thus leads tothe increase in vehicle miles of travel (VMT). For non-work trips, population density,job density and regional accessibility are direct causes of the choice of automobile, whileonly regional accessibility is causally connected to reducing automobile trips and VMT.The logit captivity model results indicate that land-use contributes to captive-drivingchoices for home-based work trips. Lack of land-use mix at trip origins increases theprobabilities of trip-makers being captive to the automobile from 0.06% to 5.62% fordriving-alone and from 0.38% to 3.55% for shared-ride.