Moving urban trips from cars to bicycles: impact on health and emissions.

OBJECTIVE

To estimate the effects on health, air pollution and greenhouse gas emissions if short trips (≤7 km) were undertaken by bicycle rather than motor car.

METHOD

Existing data sources were used to model effects, in the urban setting in New Zealand, of varying the proportion of vehicle kilometres travelled by bicycle instead of light motor vehicle.

RESULTS

Shifting 5% of vehicle kilometres to cycling would reduce vehicle travel by approximately 223 million kilometres each year, save about 22 million litres of fuel and reduce transport-related greenhouse emissions by 0.4%. The health effects would include about 116 deaths avoided annually as a result of increased physical activity, six fewer deaths due to local air pollution from vehicle emissions, and an additional five cyclist fatalities from road crashes. In economic terms, including only fatalities and using the NZ Ministry of Transport Value of a Statistical Life, the health effects of a 5% shift represent net savings of about $200 million per year.

CONCLUSION

The health benefits of moving from cars to bikes heavily outweigh the costs of injury from road crashes.

IMPLICATIONS

Transport policies that encourage bicycle use will help to reduce air pollution and greenhouse emissions and improve public health.