Would you feel safer under white or yellow light at night?

Research carried out by the University of Granada (UGR) suggests your perception of safety when walking down a street at night may be linked to the colour of the light illuminated.

The research*, published in Safety Science magazine, conducted by UGR scientists in Civil Engineering and Social Psychology, has analysed the pedestrians’ perceived safety and wellbeing when walking along streets with particular illuminance types and levels.

275 pedestrians responded to test questions after walking under public lighting, and it was found that people feel safer in streets illuminated with white light than in those illuminated with yellow light (technically called ‘sodium-yellow’).

It was concluded one possible reason was that white light allowed for better identification of human faces.

Among other results, the researchers found that the pedestrians’ reactivity to their surroundings increased with the increase in illuminance levels.

Lead author and Civil Engineering Professor Antonio Manuel Peña García said the results could be considered when deciding on public lighting regulations and added that controversy exists between different authors and philosophies about urban lighting.

“There’s no unanimous agreement on if higher illuminance levels increase street safety or, on the contrary, decrease it, given that even possible criminals seem to need a minimum level of illuminance in order to properly select their victims,” he said.

He said so far studies of higher illuminance levels to increase citizen safety have not paid much attention to people’s perceived safety with regards to public lighting installations.

*‘Impact of public lighting on pedestrians’ perception of safety and well-being’, A. Peña-García, A. Hurtado, M.C. Aguilar-Luzón, Safety Science, Volume 78, October 2015, pp 142–148.

Image caption: A street illuminated with white light (LED lamps) and another one with sodium yellow light (high-pressure sodium or HPS lamps). © University of Granada.