Lighting for cyclists

We reviewed policy and guidance for cycling and studies of road collisions involving cyclists.

Lighting has a role to play in reducing the hazards of cycling by enhancing the visibility and conspicuity of cyclists to drivers.

Lighting guidance is out of date. The two most current national documents (ILP and Sustrans) refer to out-of-date versions of BS5489. Furthermore, there is no evidence that even those recommendations take any account of the needs of cyclists.

Fotios S, Castleton HF. Lighting for cycling in the UK – a review. Lighting Research and Technology, 2017; 49(3); 381-395.

To demonstrate that lighting matters to cyclists we analysed the data from cyclist flow counters to compare cycling rates in daylight and dark. To offset other factors such as time of day and purpose of cycling, we used two approaches for comparing cyclists counts in daylight or dark but at the same time of day. Control hours are used to counter other external influences such as weather.

In this first analysis we used the clock-change approach. This is a comparison of cyclists counts for a specific time of day in the few days before and after clock changes in spring an autumn.

This analysis suggested that ambient light matters: for a given time of day there are more cyclists when it is light than when it is dark.

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.

A second analysis of the cycle count data was carried out using a different method of analysis. This is the whole-year approach: a time of day is chosen that is in daylight for part of the year and dark for the other part.

The conclusions of the first analysis were supported: for a given time of day there are more cyclists when it is light than when it is dark.

Fotios S, Uttley J, Fox S. A whole-year approach showing that ambient light level influences walking and cycling. Lighting Research and Technology 2019; 51(1): 55-64.

To see, a cyclist can benefit from road lighting and forward cycle lighting. We used a detection experiment to compare visual performance benefits of these systems and their interaction.

For cycle lighting to see, the results suggest this is better when mounted at the wheel hub than when on the handlebars.

When there is road lighting, the simultaneous use of cycle lighting can hinder the ability to detect hazards.

Fotios S, Qasem H, Cheal C, Uttley J. A pilot study of road lighting, cycle lighting and obstacle detection. Lighting Research and Technology 2017; 49(5): 586-602.

In the search for remedies to road collisions involving cyclists, lighting is not the only answer. For example, even in daylight, there are many collisions where the driver claims to have looked but didn’t see.

In work with Alexandra Bohm of Lincoln University we are exploring the role of legal responsibility. If motorists were automatically presumed liable for any collisions involving a vulnerable road user (eg a pedestrian or cyclist) this may encourage them to take more care. Such an approach is common in nearly all European states, but not in the UK.

Fotios S, Bohm A. Road lighting and accidents: Cyclists, lighting, accidents and responsibility. Lighting Journal, 2017; 82(5); 28-32.

In this study the travel count method was extended to investigate the impact on light level on cycling numbers. This was done by plotting the ambient light level odds ratio for each location against a measure of light level at that location.

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

Ongoing work

Based on our own research and that from other research groups we think there is a better way to light cycles.

Our pedestrian lighting research is leading towards new guidance for subsidiary roads: we need to be certain that any such changes do not disadvantage other road users such as cyclists.

We are working with others to seek funding to test our proposed cycle lighting and the interaction of this with road lighting.