Thousands of motorists were caught trying to push the speed limit by mobile enforcement units in 30mph zones last year, figures have revealed.

A total of 4,030 offences were recorded for vehicles travelling at 35mph in a 30mph zone across Suffolk during 2020.

Another 2,928 offences were recorded for vehicles travelling at 36mph.

Meanwhile, not a single offence was recorded for vehicles travelling at speeds of between 31mph and 34mph, as Suffolk Constabulary applied National Police Chiefs' Council guidelines recommending a margin of tolerance equal to 10% of the speed limit, plus 2mph.

The number of motorists caught travelling at 35mph or 36mph on more built-up roads by enforcement vans, or police officers equipped speed cameras, fell by almost a third during a year in which traffic levels also dropped significantly.

The fall interrupted a trend of annual increases of 41% and 31%, according to figures obtained under the Freedom of Information Act.

Last October, Department for Transport (DfT) data showed that 54% of cars exceeded the limit in 30mph zones in 2019, with the average speed being 31mph, and a fifth of all cars exceeding the limit by more than 5mph.

The data also showed that 88% of speeding offences resulted in conviction at courts in England and Wales – although most are dealt with out-of-court by way of fine or penalty points.

Suffolk Constabulary stressed that the NPCC's '10%+2mph' recommendation serves as a guideline, rather than a rule.

Although the force applies the guidance on all fixed and mobile cameras, individual officers also can use greater discretion based on surrounding circumstances.

A police spokeswoman said: "NPCC guidelines state that 35mph and above would be a ticket and they're the guidelines we like to follow.

"We have moved our thresholds before and we can still issue tickets below the threshold."

Speed is one of the 'fatal four' most common causes of serious and deadly collisions on the country's roads, along with using a mobile phone, not wearing a seatbelt and drink or drug-driving.

The risk of killing a pedestrian in a collision is between 3.5 and 5.5 times higher at 40mph than at 30mph, according to DfT studies.