The UK's largest independent road safety charity, the Institute of Advanced Motorists IAM), has found that 70 percent of drivers think the national speed limit should be increased by at least 10mph.

A poll of 2,000 people found 60 percent of those surveyed were more likely to adhere to an 80mph limit than they are to the current national speed limit.

The IAM, which is responsible for the advanced driving test, found that 60 percent of people admitted to breaking the 70mph speed limit when traffic is free-flowing, with 20 percent of those admitting to travelling at 80mph or faster.

These findings support figures released by the Department for Transport, which found that 52 percent of cars break the 70mph limit and 16 percent of those exceed 80mph.

IAM director of policy and research Neil Greig said: "Even though motorways are the safest roads, increasing the motorway speed limit is a controversial subject. This is why we want to see a trial to test its impact on road safety, fuel consumption and driver behaviour. A new 80 miles per hour limit would need to be properly enforced to make sure that it does not become an excuse to drive at 90."

"Shortening journey times for people travelling at quieter times, as Transport Secretary Philip Hammond suggests, is a good idea, providing it doesn't have a negative effect on safety," he said.

Russell Campbell - 20 May 2011