Potential of converting short car trips to active trips: The role of the built environment in tour-based travel

Objective: To better understand trip-chaining patterns and mode choice of various urban forms, this study examines the effects of land use on travel mode choice and analyzes the concept of neighborhood design in the substitution of short car trips by other transportation modes. Methods: A 'tour' is defined as a home-to-home loop of individual trips, including all the stops made along the way. This paper develops tour-based, mode-choice models and conducts integrative assessments to determine the relative influences of the various factors associated with tour-based travel and activity space environments for short round trips. Results: The short round trips most likely to require a car tended to be either commuting trips, trips involving heavy goods, or trips that link two or more stops. Transit trips for short-distance travel were likely to involve trip chaining, while most shopping trips comprised a single outing with no trip chaining. A key to increasing travel by walking was a concentration of retail shops and service providers near people's homes whereas street networks and a good regional accessibility encouraged cycling and transit use respectively, although potential spurious effects cannot be fully determined. Conclusions: Policymakers in LA who hope to increase walking should focus on the concentration of business activity in a compact commercial core in residential areas, while transit agencies in LA should consider trends like chained trip-making and restructure communities and central places with much greater transit accessibility. These strategies for local urban design and regional accessibility are likely to affect people's decisions concerning travel mode mostly in non-work travel without intervening stops; therefore, personal vehicle use can be reduced more easily by focusing on trips for leisure time activities and personal business activities near residential locations rather than on work commutes.