In this paper, we explore the transportation-land use policy connection. More specifically, we consider the question: can land use policy be used to alter transportation behavior? The answer is of some importance. If the answer is yes, then there is hope that land use policies can be designed and implemented that will bring some relief to the gridlock and complex transportation problems facing US metropolitan areas. This is the underlying assumption behind most smart growth policy reforms. If the answer is no, then land use policy may still be important, but is not likely to play an important role in resolving transportation issues. We proceed as follows. First we offer a schematic that identifies necessary conditions for land use policy to play a role in addressing transportation issues. Specially,we argue that for land use policy to play an effective role, three conditions must hold. First, land use must be able to alter transportation behavior. Second, transportation infrastructure must not fully determine land use. Third, the condition on which we consider most extensively, land use policy must significantly and constructively affect land use. After presenting the schematic, we consider the evidence on each of these conditions. Based on our review of the evidence, we conclude that land use policy can play an effective role in addressing transportation issues, but that the role is likely to be small, often counter productive, and most effective at the neighborhood scale.