Four in 10 drivers admit regularly speeding in 20mph zones

It also found a fifth of motorists admit go past the limit on a weekly basis, with a quarter saying they do so at least once a month.

The figures will not be welcomed by residents in Portsmouth, the first city in the UK to have 20mph limits on all residential roads.

The survey, by road safety charity Brake and insurer Direct Line, looked at motorists’ attitudes to the reduced urban limits.

Many 20mph limits are in place near schools to make walking and cycling to school easier and safer for children.

Brake campaigns advisor Alice Bailey said: “All parents want to know their children are safe while travelling to and from school and playing outdoors.

“Speed limits are in place to keep all road users safe and if tragedy strikes and a child is hit by a car, the speed at which it is travelling could be the difference between life and death.”

The limits were introduced in Portsmouth between 2007 and 2008 after complaints that motorists were driving too agressively on roads with 30mph limits, even when cars were parked on the side of the road.

Ms Bailey added: “20mph limits benefit our communities in so many ways, keeping them safer, cleaner and greener; when limits are lower, many more people choose to ditch the car completely and walk and cycle instead.

“If people feel they have to drive, the lower speed limit will have a negligible impact on travel times and bring so many other positive effects.”

Direct Line’s director of car insurance Rob Miles said keeping to the speed limit was a “simple way” to help keep roads safe.

He added: “We urge drivers to be conscientious and to remember that speed limits exist for very good reasons and that it is a legal requirement to observe them.”