SATURN: Supporting Active Travel Using Road-lighting at Night

Cycling is good for the cyclist and is good for society in general. People who cycle rather than drive improve their physical fitness and general health. Cycling rather than driving reduces air pollution, reduces carbon emissions and reduces traffic congestion. It also benefits local economies, as research shows cycling-friendly neighbourhoods encourage more use of local shops. Savings to public health costs through increased physical activity also means cycling benefits the national economy. The UK Government has recognised the benefits of cycling, particularly in response to the Covid-19 pandemic, through increased investment in cycling infrastructure and a new strategy to promote cycling.

Darkness puts some people off cycling, particularly women. For those who do cycle at night, there is a greater risk of being involved in a crash. Road lighting can mitigate both of these problems. Road lighting can improve the visibility of cyclists to drivers and thus reduce the frequency and severity of road traffic collisions. Road lighting encourages people to cycle when it is dark - they feel safer. However we do not know what lighting conditions best meet the needs of cyclists. Existing evidence about lighting for cyclists is weak, and current guidance about lighting for cyclists is based on out-of-date standards that focus on the needs of pedestrians rather than cyclists.

SATURN (Supporting Active Travel Using Road-lighting at Night) will provide evidence to help find the best lighting conditions for cycling, to both encourage people to cycle after-dark and to make them safer.
We will first measure the effect of darkness (compared with daylight) on the number of people cycling and the number of vehicle collisions involving a cyclist. This will be done using a method of analysis that isolates the effect of lighting from other influential factors, a method we have refined in recent pilot studies. We will use cyclist count and collision data for a range of locations in 6 major cities. These data will come from a number of sources including automated cyclist counters, crowdsourced cycling trip data and the national database of road collisions. This will tell us the size of the effect darkness has on cycling rates and collision risk at each location. We will then compare this to metrics of the lighting at each of the locations, measured using a mobile array of sensors and backed up using existing night-time aerial photography images. This comparison will reveal the relationship between lighting and cycling rates and safety, allowing us to identify the most appropriate lighting levels to support cycling.

Results from this analysis of cycling rates, collision rates and lighting will be added to the Cycling Infrastructure Prioritisation Toolkit (CyIPT), a Department for Transport-funded online tool for helping local transport planners develop and prioritise decisions about cycling infrastructure in their local area. This will help ensure SATURN has real impact and influences transport planning decisions related to cycling infrastructure. We will also use the SATURN findings to influence revisions to national and international road lighting standards, to ensure these standards take account of the needs of cyclists using the best available evidence.