Fourteen planned schemes, including 11 already on pause and three set for construction, will be ditched due to finances and low public confidence, Number 10 has said.

Existing stretches will remain but be subjected to a safety refit so there are more emergency stopping places.

It will help create 150 more emergency areas for broken-down cars along carriageways.

Smart motorways are a stretch of road where technology is used to regulate traffic flow and ease congestion.

They were introduced in England in 2014 to ease congestion – and there are 375 miles of smart motorway, including 235 miles with no hard shoulder.

But there have been longstanding fears after high numbers of fatal accidents involving vehicles forced to stop in live lanes, without a hard shoulder, only to be hit from behind.

They also use the hard shoulder as an extra lane of traffic, which critics claim has led to road deaths.

Around 10% of Britain’s motorway network is made up of smart motorways.