Smart traffic lights could cut emissions by a quarter

Is this the future for better traffic flow in urban areas? Smart traffic lights are now being tested in Britain. Graeme Paton discusses latest developments in an article on The Times website.

Smart traffic lights get green light for cutting emissions by a quarter

A new generation of smart traffic lights could be introduced after a government-backed trial showed that eliminating unnecessary stops at junctions can cut emissions by a quarter.

Research suggests that congestion levels and pollution were reduced using the technology which tells motorists how fast to drive on the approach to lights to avoid hitting them on red.

Under the system, information is sent to dashboard-mounted devices in vehicles about two thirds of a mile away from a junction, instructing motorists to speed up or slow down to maximise their chance of catching a green light.

The technology was used for four months by Highways England and the consultants Amey on two motorways around Greater Manchester as part of a £825,000 trial project.

Initial analysis of the results on the M66 and A627(M) suggests that carbon dioxide emissions from vehicles were reduced by as much as 27 per cent by minimising the number of unnecessary stops at the lights. Emissions levels can rise as vehicle engines are revved from a stationary position.

It also led to a 17 per cent reduction in levels of nitrogen oxides from engines, which is linked to poor air quality. The most impressive results were from HGVs, which can produce higher levels of emissions.

The technology — Green Light Optimal Speed Advisory — has previously been tested on the A2 and M2 in the southeast of England and on the A45 Coventry Road in Birmingham.

Highways England said that the results were promising and were now being analysed before the next steps were agreed. There are mounting concerns over the impact of polluting vehicles. Each year air pollution is estimated to cause 40,000 premature deaths in Britain and The Times has been calling for tougher action as part of the Clean Air for All Campaign.

Paul Doney, director of innovation at Highways England, said: “Though we have still some work to do to qualify the initial data, we are very excited at the early results. By using connected technology to optimise a vehicle’s speed at junctions, it’s an opportunity to not only reduce pollutants, including carbon emissions, but to give a better experience to customers as well.”

The technology involves using a sat-nav-style device on the dashboard, which takes readings from the traffic lights and advises drivers of the speed to attain. If the vehicle is required to stop, it also provides a countdown to green.

The trial involved two vehicles — a van and HGV — making 400 trips to analyse the emissions impact with and without the technology.

Paul Rose, technical director for intelligent mobility at Amey, said that the technology could be relatively easily introduced by councils or other highway authorities to cut pollution. He added: “By allowing drivers to regulate their speed, to co-ordinate with traffic-light timing, it will also minimise being stopped by a red light, easing frustration and saving motorists fuel.

“This can be achieved without the need for significant amounts of new infrastructure.”

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