Health impact assessment (HIA) and comparative risk assessment (CRA) are important tools with which governments and communities can compare and integrate different sources of information about various health impacts into a single framework for policy-makers and planners. Both tools have strengths that may be combined usefully when conducting comprehensive assessments of decisions that affect complex health issues, such as the health risks and impacts of transport policy and planning activities. As yet, however, HIA and CRA have not been applied widely to the area of transport. We draw on the limited experience of the application of these tools in the context of road transport to explore how comparative assessment of transport risks can contribute to HIA of transport policies.