The day we meet, muted grey daylight and thick fog surround the angular brick buildings of Lund University. A giant letter A hangs on one of them – A for Architecture – and in front of it lies a cobblestone square framed by red and brown beech hedges. Some twenty bicycles are parked higgledy-piggledy on leaves on the ground.
“In this part of the world, outdoor lighting is essential for our quality of life in winter. It affects how we move about and how we can make use of our urban surroundings,” Maria Johansson, Professor of Environmental Psychology at Lund University, says. “Thus light sets a limit for the distance at which we can recognise facial expressions, which in turn can affect our feeling of security.”
How people experience a town after dark depends on the quality, direction and quantity of the street lighting as well as on factors such as the colour of the light. Environmental psychologists involved in urban planning find it hard to say exactly what is best and, instead, try to measure how people experience it overall – for example by allowing them to experience and assess alternative forms of lighting in real environments. Researchers have noticed that many people prefer a warmer more yellowish light to the cooler blue usual in the first LED lamps, especially at more northerly latitudes.
Encouraging night time activity
In her research, Johansson examines the types of light that encourage people to cycle more in urban surroundings.
“The design of street lighting in cities used to be left up to traffic engineers. They tended to stress light quantities and pure safety aspects, such as if there was sufficient light for motorists to see cyclists in dark surroundings,” Johansson explains. “But we have to make a distinction between safety and security, and the latter has a lot to do with feelings and experiences.”
The absence of light doesn’t always have to be experienced as threatening – in fact, darkness can also be a privilege, says Johansson, and illustrates this with an example from research currently being pursued at King’s College in London:
“London’s socially deprived neighbourhoods used to be brightly lit, the idea being to light up areas of high crime sufficiently to allow the use of surveillance cameras. Instead of contributing to security, the harsh light suggested an insecure environment.”
The study also compared this with more affluent neighbourhoods whose building facades were discreetly lit. Although the ambient light was not so bright, it was experienced as cosy by the residents.
So, can cities become more sustainable with more and better lighting? In terms of social sustainability, the answer is yes – if it leads to people feeling more secure and increasing their freedom of movement. Though more lighting can also lead to higher energy consumption.
But in terms of lower overall energy consumption, it remains to be seen whether more people walking and cycling instead of using cars and public transport has an impact.
“Until then, we should aim at a reasonable balance between energy-efficient lighting and positive experiences. But we hope to have a definitive answer soon,” Johansson concludes.
New possibilities when street light networks are upgraded with data
The construction of Sweden’s first “internet” for lamp posts started in January 2015 in Askersund. Vattenfall developed the technology, which opens up a host of new possibilities in addition to direct remote control of outdoor lighting.