Discussion of “How to Have Sustainable Transportation without Making People Drive Less or Give Up Suburban Living” by Mark Delucchi and Kenneth S. Kurani

Delucchi and Kurani ( 2013 ) propose a sustainable transportation system that addresses the many problems caused by motor vehicles, while allowing people to retain the advantages of 'personal automobility' and low-density suburban living. They argue that reducing the 'high kinetic energy' needed for current motor vehicles [fast, heavy motor vehicles (FHVs)] should be targeted because using these vehicles contributes to a range of problems including air pollution, traffic congestion, global warming, dependence on fossil fuel, traffic injury, poor street- scape aesthetics, and social fragmentation. To address the negative impacts generated by FHVs, the authors propose separate road network systems: one for FHVs and the other for low-speed, low-mass modes (LLMs), which include the use of lightweight vehicles, walking, and cycling. Their paper then discusses an urban settlement and transportation-infrastructure scheme that incorporates both of these networks. The authors conclude that their proposal could resolve a number of issues posed by the high reliance on private motor vehicles. In this article, we discuss three issues that arise from their proposal: first, the soundness of their assumption about consumer preferences for car-based mobility and suburban living; second, the adverse land-consumption impacts of promoting private auto use and low-density suburban development; and third, the unintended negative health consequences that may arise..