Enhanced cycle provision
Well connected, high quality cycling infrastructure plays a significant role in encouraging mode shift to cycling from driving. Car trips less than 5km are considered 'switchable' to cycling in the literature. According to the literature, shorter car trips are often considered 'switchable' to cycling. While most successful in urban areas with a high density of short trips, cycling can play a strong role in non-urban areas especially when combined with other sustainable modes.
Studies have found distance/travel time, topography, and perceived safety are strong determinants of cycling uptake. Infrastructure, and policies to increase the speed and comfort of door-to-door travel, will have the strongest impact and can have a strong impact under suitable circumstances. This includes creating direct routes, minimising intersections, minimising changes in elevation, favourable traffic light control, allowing contraflow traffic, cycle lifts, e-bike sharing, and providing easily accessible, at-grade storage at the beginning and end of journeys. Studies demonstrate isolated improvements have little impact on mode shift; networks of infrastructure that connect users with desired destinations are much more successful in encouraging uptake. A Copenhagen study reports that cyclists were much more satisfied with the enhanced cycle highways, two years after the improvements, compared with a control area where improvements were not made. Induced trips only accounted for about 4-5% of trips two years after implementation, but the impact may continue to grow over a longer period.
In commuter towns, there is large potential for cycling to rail stations. In the UK, 60% of the population lives within 15 minutes of cycling to a rail station, but only 2% of users’ cycle to the station. Having the facilities and confidence to cycle to the station as part of a daily commute encourages an overall more sustainable trip compared to driving the whole route. It can also reduce the need for car ownership, which can then encourage more sustainable trip choices for non-commute trips as well. With the rising popularity of e-bikes, the preferred range for active travel can also be extended comfortably from around 5km to over 10km. They are also more accessible to individuals with limited mobility, encourage car-free households, and allow farther travel. They have strong potential in peri-urban areas if there is access to infrastructure.
While short car trips (<5km) make up a larger portion of trips - half of all trips in a Cardiff (Wales) study and two thirds of trips in Germany for example - their collective carbon impact is smaller. Almost 75% of emissions are from the 15% of trips which are long trips. Therefore, the potential for direct CO2 reduction with increased cycling is lower than other measures. While the main driver for cycling infrastructure may not be decarbonisation, it is a co-benefit to the health and safety impacts, congestion alleviation, and built environment improvements which can be the primary reason to encourage cycling. In addition to this limiting factor, there is also mixed evidence on the carbon reduction potential of new cycling infrastructure, as detailed below. The primary reasons to encourage cycling, include numerous positive impacts on health, congestion alleviation, and built environment improvements associated with modeshift. The decarbonisation potential of cycling infrastructure remains mixed and cannot be the only focus in climate mitigation policies. Coupled with other measures, it may have stronger impacts.
A number of studies quantify CO2 impacts of mode shift to cycling. In a study of Cardiff half of car trips were considered short enough (<5km) to switch to cycling or walking. Taking into account individual travel patterns and constraints (based on the sample), 41% of these could substitute car trips saving nearly 5% of all CO2 emissions from car travel.
In Germany, 11% of trips (3% of total vehicle-kilometres travelled) are by bike, if 50% of all short trips were to switch to bike, this would increase the cycling share to 21% of all trips and reduce car vkms by 3%. This means 39 million vkm, daily, would be replaced which is equivalent to 8 000 tonnes of CO2 daily. Taking into account all the criteria classified by respondents, one third of trips could be replaced, resulting in 11% fewer vkm and therefore a reduction in CO2 emissions of up to 11%.
A study from Ireland finds that shifting from driving to cycling results in 134g CO2e saved per passenger-kilometre.
An e-bike study from Portland (USA) estimates CO2 reductions are in the order of 1 000 metric tons per day if 15% of trips are made by e-bike. This is an approximately 11% reduction considering Portland's current CO2 emissions are approximately 8 000 tons per day. Calculations are based conservatively on the 'dirtiest' electricity generation in USA.
A UK based study using the English National Travel Survey, highlights that encouraging multimodality, which is what cycling infrastructure in non-urban environments is meant to do, may not have an impact on CO2. When comparing similar distance trips, multimodal trips emit lower levels of emissions, however multimodality as a lifestyle change is not associated with lower emissions, because the greater levels of travel activity among these individuals offset the benefits derived from their multimodal choices. A longitudinal study in the UK analysing impacts of walking and cycling infrastructure finds limited evidence that the infrastructure led to CO2 emission reductions.
Costs associated with this measure include enhanced infrastructure for cycling, parking provision, and subsidies for bikes. Cycle infrastructure, while ideally separated from traffic (most expensive option), can be provided with lower costs if traffic speeds are lowered and the streets are designed to provide shared space through signage and preferential signalling at intersections. Costs of dedicated infrastructure may be higher in rural areas simply due to the longer distances and lower density of use. However, separated infrastructure is especially important in areas with higher speed limits. These cycleways also simplify routing which can reduce barriers to uptake by new cyclists.
Cycle storage needs to be secure and covered from weather. This can range from well-designed bike racks with simple roof structures, to underground cycle parking with secure access. Partnering with bike repair shops and providing easily accessible maintenance services close to bike parking hubs would also help increase confidence among newer cyclists.
Infrastructure for charging e-bikes will likely become increasingly important as their popularity rises.
- Health and safety benefits: encouraging physical activity can lower stress, risk of cardiovascular disease and diabetes, and noise related health impacts; it can also improve mental health. Lower levels of air pollution, from reduced congestion, benefits those with respiratory illnesses and vulnerable populations (pregnant women, the elderly, children etc.). Lower speeds compared to cars mean crash related fatalities are less serious.
- Congestion alleviation: reducing congestion means lower levels of air pollution, calmer streets, and reduced need for road space.
- Built environment improvements: lower traffic speeds, calmer/quieter streets, reduced need for car space (roads, parking etc.), allows for more permeable surfaces rather than paved infrastructure.
- Modal shifts: It promotes the shift to active transportation modes (i.e., walking, cycling, public transportation). In Montreal, Canada, the estimated modal shift associated with the implementation of a public bike sharing program from motor vehicle use to walking, cycling, and public transportation was 6483 and 8023 trips in 2009 and 2010. This change represents 0.34% and 0.43% of all motor vehicle trips in Montreal.
Vulnerable road users (cyclists and pedestrians) are more exposed to road pollution in congested areas. Separating traffic and allowing mixed, slower traffic through calmer areas can reduce exposure.
The construction of cycle lanes themselves have carbon costs associated with them. In an Irish study, the authors found that a fully isolated greenway embodies 60.4 tonnes of CO2e per km. Therefore, 102 commuters (224 400 passenger kilometres) per year would need to shift from car to cycling, to offset the carbon foot print of a 10km greenway.
ITF (2021) Transport Climate Action Directory – Enhanced cycle provision
https://www.itf-oecd.org/policy/enhanced-cycle-provision
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