Using road lighting to promote pedestrian reassurance at night

By Steve Fotios

Road lighting makes us safer and feel safer when walking outdoors at night, and brighter lighting may be better still. But the use of road lighting has unwanted consequences such as sky glow and detrimental impact on nocturnal life. There is a need for compromise between the needs of pedestrians and the needs of the wider environment

For many countries the seasonal variation in daylight hours means some journeys are undertaken in darkness. After dark, however, human vision is impaired – we cannot see so well. One measure of this impairment is that the risk of road traffic collisions after dark is much greater than that during daylight. Road lighting is installed along roads, footpaths and parks to mitigate the effect of darkness. This typically consists of a series of lanterns, held a few meters above the ground by a lamp post or a catenary cable.

In minor roads, lighting is installed primarily to meet the needs of active travel – walking and cycling. A key issue for pedestrians is the degree to which lighting promotes a feeling of reassurance: a person who feels reassured is more likely to choose to walk. This might mean choosing to walk through a park after dark rather than avoiding it, or it might mean choosing to leave the home after dark rather than choosing to stay at home or to drive instead of walking.

It is not easy to measure the influence of road lighting on reassurance.[1] A common approach is to ask people how safe or fearful they feel and compare responses across locations lit with different lighting conditions. However, asking questions which raise issues of safety or fear can inflate the degree to which responses suggest safety or fear are a problem. Furthermore, we tend to make relative judgements rather than absolute judgements, so the range of different lighting conditions chosen by the experimenter affects the evaluations made of those lighting conditions.

Optimal lighting should provide sufficient brightness for safety, and above which further increase in brightness brings no additional benefit but increases energy consumption and sky glow.

The absence of an empirical basis means that we do not know (i) if currently proposed criteria are optimal, and (ii) the implications for pedestrians of reducing light levels in response to demands for (e.g.) reducing energy consumption or sky glow.

Lighting Research and Technology has published many studies of road lighting for pedestrians. The focus of this work is the benefit of lighting for pedestrians: providing evidence of the effect of changes in lighting conditions helps to inform lighting engineers faced with pressure to reduce light levels, or to switch off lighting, to mitigate sky glow, energy use and impact on the natural environment.

We know from one study using a qualitative approach that the presence of road lighting is associated with locations where people would be happy to walk after dark.[2]  We next need to know how much light should be provided and studies have been carried out to compare the benefit of different light levels.[3],[4] Further work has investigated the benefit of lighting for people of different age, gender and mobility.[5]

Lighting after dark helps to reveal the way ahead and to reveal potential refuge if faced with an unwanted situation. Approaching other people can be a source of anxiety. Road lighting can help us to see the other people and to decide if it feels safe to keep walking or to take avoiding action. One cue for this decision is facial emotional recognition.[6] Research has therefore been carried out to investigate what lighting is needed to support interpersonal evaluations.[7],[8]

If road lighting after dark makes us feel safer, does that lead to an increase in walking. Investigations of changes in ambient light (daylight and darkness) rather than road lighting suggest that it does: for the same time of day, there are significantly more people walking (and cycling)[9],[10] in daylight than in darkness.

The research suggests that road lighting is of benefit to pedestrians. What is not yet known is the optimal light level to support pedestrians’ needs, if indeed such as optimum can be established, and the compromise between lighting to support active travel at night versus the need for dark skies.

Collection details

Key research on pedestrian lighting and perceptions of safety
Lighting Research & Technology

References

  1. Fotios S, Castleton H. Specifying enough light to feel reassured on pedestrian footpaths. Leukos 2016; 12(4); 235-243.

  2. Fotios S, Unwin J, Farrall S. Road lighting and pedestrian reassurance after dark: A review. Lighting Research and Technology 2015; 47(4): 449-469

  3. Fotios S, Liachenko Monteiro A, Uttley J. Evaluation of pedestrian reassurance gained by higher illuminances in residential streets using the day-dark approach. Lighting Research and Technology 2019; 51(4): 557-575. https://journals.sagepub.com/doi/full/10.1177/1477153518775464

  4. Bullough JD, Snyder JD, and Kiefer K. Impacts of average illuminance, spectral distribution, and uniformity on brightness and safety perceptions under parking lot lighting. Lighting Research and Technology 2020; 52(5): 626-640. https://journals.sagepub.com/doi/full/10.1177/1477153519875171

  5. Johansson M, Rosén M and Küller R. Individual factors influencing the assessment of the outdoor lighting of an urban footpath. Lighting Research and Technology 2011; 43(1): 31-43

  6. Fotios S, Johansson M. Appraising the intention of other people: Ecological validity and procedures for investigating effects of lighting for pedestrians. Lighting Research and Technology 2019; 51(1): 111-130.

  7. Yang B, Fotios S. Lighting and recognition of emotion conveyed by facial expressions. Lighting Research and Technology, 2015; 47(8); 964-975. https://journals.sagepub.com/doi/10.1177/1477153514547753

  8. Fotios S, Yang B, Cheal C. Effects of outdoor lighting on judgements of emotion and gaze direction. Lighting Research and Technology, 2015; 47(3); 301-315. https://journals.sagepub.com/doi/full/10.1177/1477153513510311

  9. 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. https://journals.sagepub.com/doi/full/10.1177/1477153517738306    

  10. 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 https://www.sciencedirect.com/science/article/pii/S0272494417300762

About the Author

Featured
Steve Fotios

Steve Fotios is Professor of Lighting and Visual Perception at the School of Architecture, University of Sheffield, where he leads the Lighting Research Group, Editor in Chief of Lighting Research and Technology, and is an Associate Director of CIE Division 4. He founded LumeNet, the research methods symposium for PhD students of lighting, and BrightLights, where new researchers of lighting are encouraged to interview the older researchers. Professor Fotios’ research focuses upon pedestrians and cyclists, establishing evidence for the benefits of lighting for these groups so that the lighting can be optimised whilst minimising unwanted consequences of lighting after dark.


 

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