SATURN: Supporting Active Travel Using Road-lighting at Night

Cycling has many health, environmental and economic benefits and should therefore be encouraged, as acknowledged in the UK Government’s cycling and walking plan [link: https://www.gov.uk/government/publications/cycling-and-walking-plan-for-england]. Previous research suggests darkness is a major deterrent to people cycling however, particularly for women. For those who do choose to cycle after dark, they tend to be at greater risk of being involved in a collision due to reduced visibility.

Effective use of road and cycle path lighting could encourage more people to cycle after dark but current evidence about lighting for cyclists is weak. SATURN aims to strengthen this evidence by providing data on the relationship between lighting, cycling rates, and cycling safety after dark.

We will measure the effect of darkness on cycling rates using an odds ratio method developed in previous work. This will utilise data from automated cyclist counters in several UK cities. Photometric surveys will also be carried out at the locations of the automated counters, with lighting metrics such as illuminance and uniformity being compared against the odds ratio to understand how lighting influences changes in cycling rates after dark. Lighting metrics will also be compared against rates of cyclist collisions, using STATS19 road traffic collision data, to understand how lighting influences cyclist collision risk.

The results from this work will be incorporated into a cycling infrastructure planning tool being developed by our SATURN collaborators at the University of Leeds. This tool will be used by transport planners when developing and prioritising cyclist infrastructure, helping ensure results from SATURN have meaningful impact.

October 2022 update

We are currently developing and refining the odds ratio method that will be used to quantify the effect of darkness on cycling rates at each automated cyclist counter location. Our PhD student, Maan Balela, has carried a range of analyses of cyclist count data in cities in the UK and beyond to better develop the odds ratio method.

We have recently presented work from SATURN at the Lux Euorpa lighting conference in Prague (September 2022).

We also have a paper based on SATURN work under review at the Lighting Research & Technology journal.

Publications

• Uttley J, Fotios S. Using the daylight savings clock change to show ambient light conditions significantly influence active travel. Journal of Environmental Psychology, 2017;  53; 1-10.

• Fotios S, Uttley J, Fox S. A whole-year approach showing that ambient light level influences walking and cycling. Lighting Research and Technology. First posted online 24/11/2017. doi.org/10.1177/1477153517738306.

• Uttley J, Fotios S. The effect of ambient light condition on road traffic collisions involving pedestrians on pedestrian crossings. Accident Analysis & Prevention, 2017; 108: 189-200.

• Uttley J, Fotios S, Lovelace R. Road lighting density and brightness linked with increased cycling rates after dark. PlosONE 2020; 15(5): e0233105.

• Uttley J, Fotios S. Cycling in the Dark. Lighting Journal 2023; 88(2): 6-8.