Abstract:Progress toward sustainable transport depends on policies that reduce the amount of travel by motor vehicles. Land use policies are an essential element of a sustainability-approach, as transport and land use are inextricably linked: land use patterns shape travel behaviour, transport investments shape land use patterns, transport is itself a sizable land use, and these relationships are self-reinforcing. These principles explain the car-oriented approach dominant in the US in which investments in highways have fuelled low-density development and car dependence. They also suggest a path toward a sustainability-oriented approach in which compact development supports walking, biking, and transit, and in which investments in these modes support compact development in a virtuous cycle. Policy is moving in this direction in California as well as many cities around the US. What is not in doubt: land use policy is essential to the goal of sustainable transport.