A breakdown organisation has told drivers they should stick to speed limits for environmental reasons, as well as for reasons of safety. GEM Motoring Assist says staying within the speed limit will not just reduce the chance of collisions, but is also “an effective way of reducing your environmental footprint”.

Although the organisation has not cited any research backing up its claims, GEM Motoring Assist says a 1 mph reduction in speed is enough to cut collisions by five percent. It also claims a car driving at 80 mph uses 10 percent more fuel than one driving at 70 mph, although again it has not cited any evidence.

Traffic on the M4 motorway near junction 28 Newport & Cardiff

It seems the European Environment Agency (EEA) broadly agrees, after conducting research that found reducing speed limits from 130 km/h (81 mph) to 110 km/h (68 mph) would cut diesel vehicle fuel consumption by two percent and petrol vehicle consumption by three percent. However, that experiment worked on the principle the limits would not be entirely respected by drivers. Were the lower limit strictly adhered to, the EEA says those figures would rise to 12 percent and 18 percent respectively.

The safety benefits of reducing speed are better documented, with the World Health Organisation saying a pedestrian hit by a car travelling at 50 mph is three times more likely to be killed than one hit by a car doing 30 mph. A study commissioned by Transport for London, meanwhile, found the introduction of 20 mph zones had coincided with a 42-percent reduction in casualties across the capital.

A spokesperson for GEM Motoring Assist said driving safely and driving efficiently were often interlinked, with both involving forward planning and awareness.

“Research categorically shows that reduced speeds mean fewer collisions, and reduced severity of collisions,” said the spokesperson. “For example, an overall 1 mph reduction in speed results in an average five per cent reduction in collisions. We also know that a car speeding at 80 mph uses 10 percent more fuel than one driven at 70 mph, while a car driven at 70 mph uses 15 percent more fuel than one at 50 mph.”

“It’s worth remembering the connection between environmentally-aware driving and defensive driving, which has long been established. Smooth, progressive and systematic driving is safer. There are few surprises and no last-minute manoeuvres. You’re doing your bit for the environment, you’re keeping your licence clean, you’re hopefully saving money and also reducing the risks you face on the road.”

Speeding car activates electronic speed limit sign in Melbury Abbas village Shaftesbury UK