Ministers are being urged to reinstate the hard shoulder on smart motorways.
The RAC issued the plea exactly a year after Prime Minister Rishi Sunak cancelled all future planned smart motorway projects, citing financial pressures and a lack of public confidence in the roads.
It is a day after the 10-year anniversary of the first stretch of all-lane running (ALR) smart motorway – using the hard shoulder as a permanent live traffic lane – opening on the M25 in Hertfordshire.
ALR smart motorways increased capacity at a lower cost than widening roads.
There have been long-standing safety concerns after fatal incidents in which vehicles stopped in live lanes were hit from behind.
RAC head of policy Simon Williams said: “There is a real irony when it comes to talking about cost pressures in relation to these distinctly unpopular types of motorway.
“While heralded as a cost-effective way of increasing capacity on some of our busier roads, a colossal amount of public money has since gone into trying to make them safer – for instance by installing radar-based technology to detect stricken vehicles more quickly, plus the creation of additional emergency refuge areas.
“This cash needn’t have been spent. The Government ploughed on with building all-lane running motorways, regardless of concerns expressed by drivers, the RAC and even the Transport Committee.
“We continue to believe that the Government should either convert existing all-lane running smart motorways to dynamic ones – where the hard shoulder is only opened to traffic during busy periods – or repaint the white line and reintroduce a permanent hard shoulder on these roads.
“In either case, queue-busting technology such as variable speed limits could remain to help ensure traffic flows as smoothly as possible.”
A Department for Transport spokesperson said: “While smart motorways are statistically among the safest roads on our network, we recognise the need for the public to feel safe when driving, and have cancelled plans for all new smart motorway schemes.
“We are also investing £900 million to make improvements on existing smart motorways, including building more emergency areas on these roads.”
A National Highways report published in December revealed that smart motorways without a hard shoulder were three times more dangerous to break down on than those with an emergency lane.
The number of people killed or seriously injured after a stopped vehicle was hit by a moving vehicle was 0.21 per 100 million vehicle miles travelled on ALR smart motorways between 2017 and 2021.
That compares with 0.07 on controlled smart motorways, which have variable speed limits but retain a hard shoulder, and 0.10 on conventional motorways.
National Highways said at the time that evidence shows all types of smart motorways are safer than conventional motorways in terms of deaths or serious injuries, and a series of safety improvements have been made since 2021.