Environmental benefits

The principle measurable environmental benefit of active travel consists of a reduction in levels emissions and pollution compared to motorised travel. While a lifecycle approach prevents any travel mode from being completely emission-free due to the impact of road, break and tire wear and the emissions arising from the production of vehicles, active travel modes are by far the lowest producers (Royal College of Physicians, 2016; Neves & Brand, 2019).

Based on 2015 data, the average European car produces an estimated 129.1 grams of CO2e per passenger-km in urban settings and 104.8 in rural ones (World Health Organisation, 2017). This is a conservative estimate as it doesn’t take into account the increased impact per mile from short journeys, especially in cold weather (Neves & Brand, 2019). By contrast, e-bikes produce an estimated 5.4 grams of CO2e per passenger-km in urban areas through energy supply emission factors (World Health Organisation, 2017).

Active travel modes also result in the lowest CO2e emissions during vehicle manufacture. Compared to the average car requiring 4.7 tonnes of CO2e per vehicle, translating into 19.9 grams per passenger-km, bicycles and e-bikes require 0.10 and 0.19 tonnes of CO2e per vehicle (4.9 and 9.3 grams per passenger-km) respectively (World Health Organisation, 2017).

Despite the clear reduced environmental footprint of active travel modes, it is important to note that at a societal level, the benefits of active travel in terms of pollution reduction are minimal unless a consequential mode shift can be achieved (Rabl & de Nazelle, 2012; Mueller, et al., 2015). If this can be realised however, there are associated benefits for public health including reductions in all-cause mortality, respiratory disease, CVD, certain types of cancer and adverse birth outcomes (Mueller, et al., 2015). Additionally, as pollution exposure is more hazardous to children, older adults, people with existing chronic health conditions and people living in more deprived areas (which may experience higher pollution levels), these groups stand to accrue a larger health benefit (Royal College of Physicians, 2016).