What makes people feel safe at night? On the science of street lights

Street lights in Kabul, shortly after they were installed for the first time in 2003. Image: Getty.

Winter is coming: the nights are drawing in and in the Northern Hemisphere the hours of darkness already outnumber the hours of daylight. Research has shown that darkness produces a big fall in the number of people out walking – and a major reason for this is that people feel less safe walking in the dark.

There may be an evolutionary explanation for why people feel less safe at night – we can’t see as well, and this may have exposed our ancestors to greater threat from predators. Nowadays, it’s not so much the prospect of being eaten by a savage beast that concerns would-be pedestrians, but the fear of being mugged or victimised.

Some studies suggest that new outdoor lighting can reduce crime rates in an area, but there is conflicting evidence on this. A large review of research found a link between new lighting and reduced crime rates, but improvements were seen in daylight as well as darkness, suggesting that street lighting is not the only factor. This review has also been criticised by other researchers, and a large statistical analysis found no link between crime rates and switching off or dimming street lighting at night.

Street lights may or may not have an effect on crime, but one thing’s for sure – brighter levels of light do make people feel safer when walking at night. This can lead to a significant increase in the number of minutes people spend walking each week. It can also reduce the number of people who avoid leaving their homes at night, reduce social isolation, improve physical and mental well-being and increase community pride.

Street lighting can improve the quality of neighbourhood life by making people feel safer – but, even so, it would be unwise to flood our streets with light at night. Street lighting costs money: the UK’s annual bill is estimated at around £220m. Artificial light at night may also have a negative impact on wildlife and the natural world, for example by stunting the growth of frogs and toads and preventing them from laying their eggs.

The skyglow from street lights also means we rarely get to see the true wonder of the night sky, frustrating astronomers and limiting our appreciation of the natural environment. For these reasons, lighting should be used selectively and efficiently – and this requires good guidance to help those responsible for installing and maintaining our street lighting.

The guidelines for street lighting in the UK and many other countries are currently based on questionable evidence. That’s why our lighting research group at the University of Sheffield undertook a programme of research to find out how lighting relates to feelings of reassurance after dark, and improve the evidence on which lighting guidelines are based.


Illuminating evidence

In one recent experiment, we asked people to walk along a number of streets in the city of Sheffield at night and rate how safe they felt. We also asked these people to walk and rate the streets in the day, to create a baseline measure of safety and to account for biases that may occur if safety ratings were taken only after dark.

The difference in safety ratings between the day and night walks told us something about the lighting on that street – the smaller the difference between day and dark ratings, the safer people felt due to the lighting. We compared our participants’ different ratings against measures of the lighting on each street, including the average illuminance (amount of light falling on the street surface) and uniformity (how evenly spread out the lighting was).

Today, average illuminance is the main measure used when installing and evaluating street lighting. But we found that, while increasing average illuminance was linked with improved feelings of safety, uniformity was more important for making people feel safe. So it might be more important to have evenly distributed lighting, rather than bright lighting, to make people feel safer.

Local authorities are undergoing major changes to their lighting, as they replace the traditional orange sodium lamps with new LED lighting. These new LEDs are more energy efficient, which saves taxpayers’ money. They also give councils greater control over the lighting they provide, for example by dimming and switching off when there are no pedestrians about.

Used properly, street lights can improve people’s lives and help neighbourhoods come alive at night. But there’s still a lot to discover about how people respond to street lighting and the impacts it has on society and the environment – experiments such as these can help to light the way.

The Conversation

Jim Uttley, Research Fellow, University of Leeds; Aleksandra Liachenko Monteiro, PhD Candidate, University of Sheffield, and Steve Fotios, Professor of Lighting and Visual Perception, University of Sheffield.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

 
 
 
 

Wild boar are moving back to Genoa, and not everyone is pleased

A wild boar, c1933. Image: Getty.

Crossing the Ponte Gerolamo Serra in the Italian city of Genoa, I spotted a small crowd clustered by the river wall. I approached, intrigued, and peered over the wall to discover the subject of their delight: a sounder of eight wild boars – the adults sheltering from the heat in the undergrowth, while the juveniles foraged among the foliage that grows in the river bed during the dry summer months.

In any other city, such a sight might have been surprising. But in Italy, and particularly in the region of Liguria, where Genoa is located, the population of wild boars has been increasing at such a rapid rate that these incidents are now common. Across the country, it’s estimated that the population has risen from 600,000 to 1m over the past decade.

But while wild boars may look comically out of place trotting about the city, it’s actually a natural result of the way people have migrated – and the wars they have fought – over the course of recent history.

Making a comeback

A species native to Europe, the wild boar (or “cinghiale”, in Italian) largely disappeared from its historical territories during the 18th and 19th centuries. Their decline was widely attributed to the combined effects of habitat change, competition for space and resources and, of course, hunting.

Wild boars were a prized quarry, revered for their ferocity – and the danger involved in pursuing them. According to local folklore from the region of Liguria, the last truly wild boar was hunted and killed in 1814, in the province of Savona.

After an absence of more than a century, wild boar began to return to Liguria, and to the neighbouring region of Piedmont. A further influx occurred during World War I, when it’s believed that military activities in the south-east of France forced parts of the population back into Italy over the Alps.

Although hunting fraternities were quick to augment this fledgling population with wild boars transported from elsewhere, the return of the species was primarily due to natural causes. From the 1950s onwards, traditional agricultural practices were abandoned as more and more people moved from rural towns into the cities. This meant that large areas of formerly cultivated terraces and pastures were rapidly overgrown, fast becoming dense secondary woodlands.

A city gone wild

This spontaneous “rewilding” has become a controversial issue in the region. Many conservationists and environmental organisations consider the region’s return to a “wild state” a success. But others believe that the encroaching wilderness signals a loss of traditional woodland knowledge and a reduction of biodiversity, associated with the pastures and meadows.


The province of Genoa is among the areas most densely populated by wild boar in Italy, with an estimated 25 boar per 10km². Rewilding processes have brought woodlands to the city limits, blurring the boundary between rural and urban areas. The species has expanded beyond the hinterlands, colonising highly urbanised, densely populated city spaces in Genoa, drawn by the abundance of food waste created by humans.

In 2009, the infamous boar Pierino made his home at Righi, on the outskirts of Genoa, where he was routinely fed with focaccia by enthusiasts. Today, a family of wild boar call the Albergo dei Poveri – a historical hostel for the Genoese poor in the city centre – their home.

But while their antics are often recorded and shared with glee on social media, the threats posed by the presence of wild animals has become a preoccupation for the city’s municipal administration.

Boorish behaviour

Wild boar have been involved in a number of traffic accidents, and have proven to be particularly dangerous when with their young, attacking dogs and even people. The city council in Genoa has put forward many proposals to reduce the number of animals in the city, ranging from forced removals, to sterilisation, increased attention to waste disposal and approved hunts. About 90 wild boar were reportedly culled in 2018.

Needless to say, each of these measures has been hotly debated. Animal advocacy groups staunchly oppose the proposals, and sometimes obstruct the authorities’ attempts to take action, often sending patrols to care for the animals, and even give them names. But other residents are displeased with the animals’ presence in the city, and have consulted with the council on how to address the problems that they cause.

And so Genoa continues to grapple with thorny issues surrounding the presence of wild boar in the city, with the city authorities seeking to resolve a polemical issue that embroils the lives of animals and humans alike. So far, a collective, coherent and communally agreeable strategy has proven evasive; one that considers the need for public safety, hygiene and health with the ethical responsibilities towards to wild boar themselves.

Meanwhile, the animals themselves continue to lounge and forage beneath the Ponte Gerolamo Serra and elsewhere, bringing a little of the wilderness into the city.

The Conversation

Robert Hearn, Assistant Professor in Human Geography, University of Nottingham.

This article is republished from The Conversation under a Creative Commons license. Read the original article.