RECORD:

While road lighting guidance alleges consideration of cyclists, there is very little empirical evidence of lighting for cyclists available to inform such guidance.  

Of particular concern is the assumption that it is appropriate to group cyclists with pedestrians (i.e. within the P class with light levels defined by illuminance). This may not be appropriate. (1) It implies the assumption that cyclists’ gaze behaviour is widely distributed and not focussed on the road ahead. (2) It assumes that lighting criteria for pedestrians are also suitable for cyclists, despite their faster travel speed, their usual placement on the road rather than on the footpath, and hence likely need for different visual information. (3) It assumes that cyclists and pedestrians desire to detect and identify objects at similar distances ahead (and hence subtend similar sizes at the eye) which is unlikely given different travel speeds and differences in the actions available for instantaneous response to hazard detection. 

One way to test these assumptions is to use eye tracking to record the gaze behaviour of cyclists and compare this with other road users - pedestrians and motorists.  There are some existing eye tracking data for cyclists. While these reveal a difference between pedestrians and cyclists they are not sufficient: they were conducted only in daylight (and light level is expected to affect gaze behaviour) and the test participants were young (<28 years) (and age affects vision and cycling stability). 

Our aim is to use mobile eye tracking to explore cyclists gaze behaviour on mixed-use roads and segregated cycle paths (a 3km route - see map below). This will be done in daylight and after dark, with young (18-40) and old (55+) cyclists, on pedal cycles and e-bikes. A parallel study will be conducted by Nick Tyler in the PEARL laboratory at UCL, to enable controlled variations in route width and travel speed, light level, and to explore also head and body movement in addition to gaze behaviour. This will extend our previous work using eye tracking to investigate the gaze behaviour of pedestrians and interpretation of those data to explore gaze towards trip hazards and other people. 

Publications

• Uttley J, Fotios S. Cycling in the Dark. Lighting Journal. February 2023; 88(2): 6-8. (Preliminary report from an ongoing analysis of cyclist crashes in STATS19)

• Fotios S, Uttley J. Cyclists are incorrectly represented in lighting design standards. Abstract submitted for the CIE2023 conference.