Public health engineering emerged from the need to tackle cholera in the nineteenth century. Transport today is a challenge comparable to cholera in the nineteenth and air pollution in the twentieth century in its complexity, cost, engineering and health consequences. Engineers dealing with the ‘low-carbon' transport agenda must contribute to carbon dioxide reduction targets as a matter of policy requirement. Cross-disciplinary synergies between low-carbon approaches and health are important to both policy fields. Transport is not an end in itself, but provides access to facilities, people, work, education and goods and can build physical activity into everyday life. Simultaneously, transport causes stress, disruption of communities, injuries and death, noise and air pollution, causing physical and mental ill-health, and is a major emitter of greenhouse gases. Benefits of motorised transport accrue particularly to the wealthy, while adverse effects fall disproportionately on the disadvantaged. Effective low-carbon policies must reduce the need to travel and promote modal shift as well as embracing technological advances. However, making transport carbon dioxide-free will neither offset all health issues nor deliver all quality-of-life requirements. This paper explores ways in which the low-carbon and health agendas are complementary, and where potential conflicts could arise.