Quantification of the Potential Health and Environmental Impacts of Active Travel in Dublin, Ireland

Many European cities are becoming increasingly dependent on motorized transportation, with impacts ranging from traffic congestion and greenhouse gas emissions to sedentary lifestyles and an increased risk of noncommunicable diseases. The promotion of active modes of travel in urban environments has the potential to mitigate the external costs of motorized transportation and improve the physical and mental well-being of transport users. The present study considered a modal shift to active travel in commuter trips in Dublin, Ireland, and quantified the resultant benefits and detriments to individual transport users and to society. The total impact was found to be strongly positive: the health benefits of increased physical activity dominated the individual benefits, and reductions in noise and congestion were the most significant external benefits. The benefits were partially offset by an increase in the cost of road traffic injuries, particularly nonfatal cyclist injuries. Women, and to a lesser extent men, in the age group 25 to 34 years old were identified as those who made the most driving trips that could be taken on foot or bicycle instead. Although some uncertainties remained, these results made a strong case for policies and investments that make cycling and walking in cities more attractive to alleviate the environmental damage caused by urban transportation and to improve public health.