A report by the Commons Transport Select Committee (TSC) published on Nov. 2 said that more data is needed on safety and economics.
Smart motorways were developed to increase capacity without having to add extra traffic lanes. They get their name from using technology to shut and slow lanes in response to accidents and breakdowns, freeing up the emergency hard-shoulder lane to be flexibly used for regular traffic when needed.
Concerns have been raised following fatal incidents involving broken-down vehicles being hit from behind.
Last spring the government decided all future smart motorways would be the “all-lane-running” versions, where the emergency hard shoulder is turned into a permanent traffic lane, and periodic escape areas added instead.
The TSC report described that the decision was “premature” and urged ministers to “consider alternative options for enhancing capacity” on motorways.
The committee’s report called for the government to pause new all-lane running until five years of data is available for the schemes introduced prior to 2020.
The report noted that by contrast “controlled smart motorways” which have a permanent hard shoulder and use technology to regulate the speed and flow of traffic, have the “lowest casualty rates” of all roads across motorways and major roads in England.
It said the government should “revisit the case” for installing them instead of all-lane running motorways.
“Looking at the available evidence, smart motorways do appear to be safer than conventional motorways even once the hard shoulder is removed,” said Tory MP Huw Merriman, who chairs the committee.
“However, this evidence is also open to question. Only 29 miles of these all-lane running smart motorways have operated for over five years.
“It therefore feels too soon, and uncertain, to use this as an evidence base to remove the hard shoulder from swathes of our motorway network.”
The report also recommended that emergency refuge areas be retrofitted to existing all-lane running motorways to make them 0.75 miles apart “where physically possible,” and a maximum of one mile apart.
Relatives of those killed on smart motorways have called for the hard shoulder to be permanently reinstalled on the roads.
But the committee says it was not convinced this would boost safety.
“The evidence suggests that doing so could put more drivers and passengers at risk of death and serious injury,” said the report.
“The government is right to focus on upgrading the safety of all-lane running motorways.”
Claire Mercer, whose husband, Jason Mercer, died on a smart motorway stretch of the M1 in June 2019, gave a mixed response to the report.
Asked about the conclusions, she told the PA news agency, “I don’t think they’re strong enough.”
But she welcomed the recommendation for the rollout of smart motorways to be paused, as “that will give us more time to get into the High Court and get these banned anyway.”
PA contributed to this report