Stop Excessive Speeders

The RAC is supporting calls for a UK trial of Intervening Intelligent Speed Assistance for serious and repeat speeding offenders. This is not about restricting every driver. It is about using proven vehicle technology to stop the small number of drivers who repeatedly and dangerously break the speed limit.

The problem

Speed remains one of the biggest risks on Britain’s roads. Too many people are still being killed or seriously injured, and progress on road safety has stalled.

Most drivers are not the problem. The campaign is focused on serious and repeat offenders who have shown that fines, points and warnings are not enough.

Speed is the main factor behind road collisions in the UK. In 2024 – the latest year data is available – speed was a factor in 58% of fatal collisions, with drivers or riders exceeding the speed limit behind a fifth of such collisions. Analysis of data by the RAC found more than 4,000 drivers who have accumulated 12 or more penalty points for speeding offences have escaped being banned and are still behind the wheel.

The solution

Intervening Intelligent Speed Assistance, or IISA, is a device fitted to a vehicle that prevents it from accelerating beyond the speed limit.

It does not slam on the brakes. It does not remove driver control. It simply stops continued acceleration above the legal limit.

RAC research carried out for the Government’s consultation on its recently published Road Safety Strategy found that nine-in-10 (86%) drivers are supportive of new measures being introduced to target those who speed excessively.

How it works

What is Intervening ISA (IISA)?

Intervening Intelligent Speed Assistance is a small device fitted to a vehicle. It uses speed-limit data, GPS and/or sign recognition to identify the speed limit and prevent the vehicle from accelerating beyond it.

IISA is not the safe as Intelligent Speed Assistance (ISA), which is fitted as standard to most new cars sold in the UK.

What happens when the driver reaches the speed limit?

The vehicle can be driven normally up to the speed limit. Once it reaches the limit, the system manages throttle input so the vehicle cannot continue accelerating unlawfully.

Does it apply the vehicle's brakes?

No. Intervening ISA does not suddenly apply the brake. It works by limiting further acceleration above the speed limit.

Can the driver override it?

A limited emergency override can be built into the system. Any override would be logged, so it could be reviewed as part of compliance monitoring.

Who would use it?

The campaign is not proposing this for all drivers. It would be used only for defined groups of serious or repeat speeding offenders, such as drivers who repeatedly speed, commit serious speeding offences, or avoid disqualification despite accumulating points.

What we're asking for

Our call on the Government

We are asking the Government to legislate for a UK trial of Intervening ISA for serious and repeat speeding offenders.

The trial should test whether the technology can reduce repeat speeding, improve compliance and protect road users.

Why a trial?

A trial is the right next step. It would allow Government to test the technology in UK conditions before considering wider use.

It would also allow the Department for Transport, Ministry of Justice, DVLA, police, courts and local areas to work through the practical questions.

Who should be included?

The trial should focus on defined high-risk groups, potentially including: