One major factor limiting the public health benefits of active transport is the perceived and real safety concerns of cycling. A recent Dutch study estimated that for individuals who shift
from car to bicycle use, the beneficial effects of increased physical activity are substantially larger than the potential mortality effect of increased inhaled air pollution and increased traffic accidents.66 But cycling safety varies, as UK cyclists are three times more likely to die than cyclists in The Netherlands.67 Evidence on the impact of cycle routes on the risk of cycling injury is currently mixed for urban roads. Creation of safe urban environments for active travel will mean improved research into built environment interventions prioritizing the needs of cyclists, which evaluates impacts on both rates of physical activity and road injury. Future policies should promote walking or cycling to become the most direct, convenient and safe option for most urban trips. Not only can urban planning policies promoting active transport result in environmental benefits to urban air pollution and long-term climate change, this review suggests that they may also improve population health.