Is it time for lights out?

Well lit night-time streets are what we expect in towns and cities. We think they make life safer, but do they? It costs around £300 million a year to light our streets – a cost that comes with a significant carbon footprint too.

Many local authorities across England and Wales have been starting to use a range of ways to reduce street lighting, from switching lights off permanently to reducing the number of hours lamps are on overnight, dimming the lights, or replacing familiar orange lamps with energy efficient LED ones. Often these changes have gone unnoticed, but a minority have voiced concerns, particularly relating to road safety and crime prevention. Are these people right to be concerned? How can we tell what is safe?

The NIHR Public Health Research Programme stepped in to help by commissioning a research team from the London School of Hygiene and Tropical Medicine (LSHTM) and University College London (UCL) to gather the evidence. Professor Phil Edwards of LSHTM said "We were contracted to assess the situation using data from 62 local authorities across England and Wales. We compared changes in crime and traffic injuries on streets and in areas before and after street lighting changed to see what differences there might be between full or reduced levels of street lighting."

As well as crunching the numbers, the research team explored the experiences of residents and workers in some of the areas being studied. They visited the areas in person and walked around them both by day and after dark in locations affected by part-night or switch-off. They spoke to a variety of residents and local workers on the streets and in focus groups and also sent out questionnaires to affected addresses. They also consulted other stakeholders such as local authority lighting professionals.

Many responses chimed with the resident who said, "Well yes, but it has been OK, we haven’t really noticed it have we?", although some people had concerns about road safety: "What it has changed for me is, because I’m a runner, I run, I can’t run early in the mornings like I used to. Or not in the winter anyway. It’s too dangerous, with all the narrow roads and that. I have to drive somewhere now to go for a run." A small number of people had actively positive reactions, like "They’ve changed them to what do you call it, low density lights – good for the stargazing – now you can see the sky ... you’ve got the whole world in front of you!"

Analysis of the actual the road accident data, however, showed no evidence of an association between reduced street lighting and night-time road casualties or crime across England and Wales. Professor Edwards said ‘The current evidence suggests that local authorities can safely reduce street lighting at night without increasing road casualties or crime, however, local authorities should consider Public concerns when they decide where and when, to reduce lighting at night.’

The team then compared crime data in the same way, focussing on offences which are generally more likely to occur at night such as burglary, theft of or from a vehicle, robbery, violence and sexual assault. Professor Shane Johnson of UCL Security and Crime Science said “The study findings suggest that energy saving street lighting adaptations have not increased area level crime in the neighbourhoods studied. This is very encouraging, but it is important to note that it does not mean that this will be the case under all conditions, and so changes to lighting should be managed carefully.”

When the evidence was published, Dave Franks, a Public Lighting Manager for Westminster City Council welcomed it, saying:

It’s vital to have independent research into this type of thing. Local authorities are under immense pressure with budget constraints and it’s good to understand if the strategies employed by the local authorities are actually achieving the right outcomes.

Further reading

Read about this project on the Funding and Awards website.

Read more making a difference stories.

NIHR is continually commissioning research to provide the evidence needed to make good decisions in areas which could impact on public health. Full reports of completed are always published on NIHR Funding and Awards, whatever the findings, and the site also shows details of studies currently underway. If you want to keep up with the latest evidence, visit NIHR Evidence, and if you know of an evidence gap about a health matter, let us know by suggesting a topic for future research.