Objective Improving cardiovascular health through increased physical activity is most promising by integrating it into daily life, for instance walking or cycling to work.Although from a societal point of view a modal shift from car to bicycle may have beneficial health effects due to decreased air pollution emissions, decreased greenhouse gas emissions and increased levels of physical activity, for the shifting individual adverse health effects such as higher exposure to air pollution and risk of a traffic accident may prevail.This paper describes whether the health benefits from the increased physical activity of a modal shift for urban commutes outweigh the health risks.Data sources and extraction We have summarized the literature for air pollution, traffic accidents and physical activity using systematic reviews supplemented with recent key studies.Data synthesis We quantified the impact on all-cause mortality when 500,000 people would make a transition from car to bicycle for short trips on a daily basis in the Netherlands.We have expressed mortality impacts in life years gained or lost making use of life table calculations.For the individuals who shift from car to bicycle, we estimated that beneficial effects of increased physical activity are substantially larger (3-14 months gained) than the potential mortality effect of increased inhaled air pollution doses (0.8-40 days lost) and the increase in traffic accidents (5-9 days lost).Societal benefits are even larger due to a modest reduction in air pollution and greenhouse gas emissions and traffic accidents.Conclusions On average, the estimated health benefits of cycling were substantially larger than the risks relative to car driving for individuals shifting mode of transport.