Planning decisions often have significant indirect effects. As planners, our challenge is to clearly describe these impacts and quantify them as much as possible so they can be incorporated into decision making. An example of this is the effect that transportation planning decisions have on human health. These impacts are significant but often overlooked or undervalued in the planning process. I have worked on several research projects that explore the nexus between transport planning decisions and public health, and are developing practical tools for incorporating them into planning. Let me share some of my current thinking about this issue.