The literature on the impact of urban form design on travel behavior reveals mixed results. Instead of interpreting this finding as an insufficient basis for warranting action, this article suggests that a precautionary approach be introduced. This approach should be based on two interdependent modes of knowing and doing to establish and evolve design exemplars in conjunction with discipline-based analytical exemplars. Even if trends, including the digitization of human life and society, peak oil and climate change turn out to have smaller negative effects than is currently anticipated, we will be ahead with more livable and sustainable urban forms. (Contains 2 notes.)