‘Social influence’ deters engine idling, researchers suggest

Using signage with messages informed by behavioural science can help to encourage car drivers to turn off idling engines in areas of high air pollution, new research has claimed.

The findings follow a five-week project conducted by researchers from the University of East Anglia (UEA), in collaboration with Norwich city council and Norfolk county council’s Transport for Norwich initiative.

Signs bearing messages informed by behavioural science can help to influence drivers to switch off their engines when stationery, researchers have claimed

As part of the project signs based on psychological theories of social influence were placed at a traffic light controlled junction on Riverside Road in Norwich, an area that currently exceeds the national objective for levels of nitrogen dioxide, for three weeks.

The trial – which was conducted between October and November 2017 – examined whether there was an increase in the number of people who turned off their engine in the presence of a sign.

The three signs used, for one week each, read:

• Think about your actions. When the traffic lights are red, turn off your engine.Join other responsible drivers in Norwich.
• Switch off your engine when the traffic lights are red.
• Turn off your engine when the traffic lights are red. You will improve air quality in this area.

The behaviour of 4,660 cars drivers was observed over the trial period, and suggested that before the introduction of the signs only 9.6% of people turned off their engine when waiting at a red light. This increased to 17% when a sign was present.

Results also suggest there was a lasting benefit even after the signs were taken down, with motorists continuing to switch of their engines, the researchers said.

Psychological theory

Dr Rose Meleady, a lecturer in psychology at UEA, led the trial and said that although councils already use signs to influence driver behaviour, using messages drawing on psychological theories of behaviour change could increase compliance.

She said: “Traffic and vehicle pollution is a primary contributor to poor air quality and idling traffic is of particular concern. Our research shows that using psychological theory to inform the design of road signs can help bring about changes in driver behaviour. Rather than simply telling people what do to, the signs are designed to tap into the underlying motivational basis for behaviour.

“While there are stop-start technologies being developed for cars, this is a simple, cheap, site-specific method of encouraging positive behaviour change. It is also a good example of working together with local authorities on an important issue – how to get people to turn off their engines and ultimately reduce air pollution. We’d like to work with others in this way.”

Behaviour change

The work is part of a larger project, led by Professor Dominic Abrams of the University of Kent, with a team of social psychologists from UEA and the University of Lincoln.

Initial research carried out by the group suggested that using a series of signs based on psychological theories of behaviour change could increase compliance with an instruction to turn of engines while waiting at a level crossing.

The trial in Norwich comes as the council considers measures to fine motorists who leave engines idling in a bid to tackle air pollution.

Councillor John Fisher, chair of Norwich Highways Agency Committee, said: “Air quality is an important issue facing cities across the country and work like this is a valuable step in understanding what measures we can take to keep emissions as low as possible. Initial findings from the Riverside Road study are promising so we’d like to continue our collaboration with UEA and look for funding opportunities to explore this approach to behaviour change further.

“We’re pleased to have supported the research through Transport for Norwich — it’s a real asset to have this sort of expertise on our doorstep and I’m delighted we’re using it to look at ways of addressing such an important subject.”

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