Management strategies have resulted in significant improvements in air quality in most urban areas of the world. Despite general trends toward improved air quality, urban air pollution remains a concern with clear evidence of substantial public health impacts. Motor vehicles are major contributors to ambient air pollution and their emissions result in variability in pollutant concentrations within cities. Air pollution and climate change are linked through common emission sources and health impacts. For example, increases in the frequency and intensity of extreme heat events are expected to coincide with increased summer smog episodes and their resulting cardiovascular and respiratory health impacts. Climate change adaptation will require increased application of traditional health protection measures, while greenhouse gas mitigation efforts must not compromise air quality. Climate change mitigation offers opportunities for co-benefits through which greenhouse gas emissions are reduced in combination with reductions in emissions of health-damaging air pollutants. Healthy urban design, in which active transportation is facilitated, can lead to emission reductions while providing further potential health benefits through increased physical activity. In this presentation I will present findings of epidemiological studies associating adverse health impacts with spatial variability in pollution levels related to transportation, describe air pollution mitigation strategies, and discuss implications of this emerging body of research for healthy urban design.