Protesters have carried coffins across London’s Westminster Bridge to represent deaths on smart motorways since they were introduced in a bid to ease congestion.
Around 50 demonstrators marched to Parliament Square on Monday to demand a ban on all-lane running (ALR) motorways, which can convert the hard shoulder into a live traffic lane.
There have been mounting concerns about such motorways after several fatal accidents involving stationary vehicles being hit from behind.
The action was led by Claire Mercer, whose husband Jason Mercer died on a stretch of the M1 without a hard shoulder.
Mr Mercer, 44, and Alexandru Murgeanu, 22, died near Sheffield when a lorry crashed into their vehicles which had stopped on the motorway after a “minor shunt” in June 2019.
Mrs Mercer told the PA news agency the protest aimed to “force home the message that we’re just being ignored by the Government”.
She said: “They keep doing review after review after review. In the meantime, people are still dying.
“There’s a really strong feeling against these. We need to embarrass the Government into actually doing something.
“We don’t need a raft of changes. We just need the hard shoulder back in every single instance.”
As well as carrying 38 cardboard coffins, protesters held placards that read “How many more have to die?” and “Will you listen when it’s a coach full of school kids?”.
Mrs Mercer, from Rotherham, said the number of coffins corresponded to the official number of people killed on smart motorways between 2014 and 2019.
“Obviously that data is now out of date. The true figure is much much bigger,” she said.
She added that her campaign is educating the public about the risks of smart motorways.
“My husband might still be alive if he’d known what a smart motorway was,” she said.
Labour MP Jim McMahon, the shadow transport secretary, said his party “would reintroduce the hard shoulder today”.
He told PA in Parliament Square: “Smart motorways have their role to play in increasing capacity and allowing traffic to flow more freely.
“Where we strongly disagree with the Government is the idea that you can switch off the hard shoulder, that you can take away that vital safety net that gives people protection if they’re stranded.”
Jack Szwarc, 33, who was wearing a leg brace, said he almost died on a smart motorway in April.
The 33-year-old from Wolverhampton said he came off his motorbike at 60mph on the M6, having nowhere safe to escape when the engine died.
“Smart motorways almost cost me an arm and a leg,” he told PA, describing how his bike slammed against the barrier, causing him to lose “a big chunk” of his leg, shatter his kneecap and dislocate his shoulder.
“We’re all here as receipts from the hidden costs of profits over people,” he added.
National Highways, the Government-owned company responsible for England’s motorways and major A roads, said the chance of death on smart motorways is less than on any other major road.
The company’s chief executive Nick Harris said: “Every road death is a tragic loss of life and our thoughts remain with those who have lost a loved one.
“Safety remains our top priority and our motorways are the safest type of road in the country.
“Data shows fatalities are less likely on smart motorways than on conventional ones, but we recognise concerns continue to be raised.
“We are determined to do all we can to help drivers feel safe and be safer on all our roads. We will work with drivers to make increasingly busy motorways safer for everyone who uses them.”
The Commons Transport Select Committee is due to publish a report on Tuesday on the rollout and safety of smart motorways.