SMART motorways in the UK have come under criticism after a report said it is not safe to continue with the project.

This comes after the Chronicle reported that work on the smart motorway on the M3 between Winchester and Southampton is moving forward with preparations almost complete.

A report by the Commons’ Transport Select Committee (TSC) said there is not enough safety and economic data to justify continuing with the project.

The committee’s report said: “The Government and National Highways should pause the rollout of new all-lane running schemes until five years of safety and economic data is available for every all-lane running scheme introduced before 2020 and the implementation of the safety improvements in the Government’s action plan has been independently evaluated.”

On Monday, demonstrators protesting against smart motorways marched with coffins to the Houses of Parliament.

In response to the TSC's report, a Department of Transport spokesperson said: “We welcome the Transport Committee’s scrutiny and will now consider its recommendations in detail, providing a formal response in due course. This is a serious piece of work which we will engage with closely in the months ahead.

“We’re pleased that the TSC recognises that reinstating the hard shoulder on all all-lane running motorways could put more drivers and passengers at risk of death and serious injury and that we’re right to focus on upgrading their safety, as the Secretary of State committed to doing when he became Transport Secretary.

“We recognise that improvements have not always been made as quickly as they could have been in the past, but as the committee has set out, the Transport Secretary is absolutely committed to making Smart Motorways as safe as possible, including committing £500 million on upgrades and the faster rollout of Stopped Vehicle Detection.”

In relation to the work on the M3, National Highways said: “We’re planning on moving to the next phase of preparations work to upgrade the central reservation later this year, before aiming to start on the main all-lane running associated works next spring.

“We’ll provide an update as we move closer to the next phase of preparation work.”

Smart motorways were first introduced in England in 2014 as a cheaper way of increasing capacity compared with widening carriageways.

There are about 375 miles of smart motorway in England, including 235 miles without a hard shoulder.

An additional 300 miles are scheduled to be opened by 2025.