Road traffic collisions

RTCs at pedestrian crossings were examined using the clock-change approach to isolate the effect of ambient light. The analysis confirmed expectation of an Increased risk of pedestrian RTC at crossings after-dark compared to daylight.

The analysis also compared RTCs at pedestrian crossings versus non-crossings. This revealed that the risk of pedestrian RTC after-dark is greater at crossings than at other locations. One explanation for this is that pedestrians are over-confident of been seen when using a crossing.

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

While statistical analyses of RTC records have shown that road lighting reduces the frequency of collisions after dark, this does not mean that lighting can be expected to prevent specific collisions. There are cases where the absence or insufficiency of lighting is unlikely to be a causal factor. It is important to recognise this because it may help prevent local authority funding being incorrectly spent. This article focuses on one specific RTC where fatigue and walking back to the vehicle were more likely to have been causal factors than the coroners’ proposal that “if there had been lights in this area .. the collision would not have occurred”.

Fotios S, Price T. Road lighting and accidents: why lighting is not the only answer. Lighting Journal 2017; 82(5); 22-26.

In this paper we investigated the influence of ambient light level (daylight vs darkness) on the prevalance of different types of road traffic collission involving motorcyclists.

Robbins CJ, Fotios S. Motorcycle safety after-dark: The factors associated with greater risk of road-traffic collisions. Accident Analysis and Prevention 2020; 146: 105731.

Comparing events taking place at the same time of day but when that time of day changes from daylight to darkness (e.g. across a clock change) provides an interesting analysis of the effect of light. In this we explore that methodology.

Fotios S, Robbins CJ, Uttley J. A comparison of approaches for investigating the impact of ambient light on road traffic collisions. Lighting Research and Technology 2021; 53(3): 249-261