Smart motorways are to be investigated as part of a wide-ranging review into UK motorway safety.
They were were first introduced in England in 2014 and are built and managed by Highways England.
They aim to keep traffic moving by converting the existing hard shoulder into an “active” fourth lane and controlling speed limits.
There are also emergency pull-ins, or refuges, in case a vehicle needs to stop, although campaigners say these are spread too far apart.
Safety campaigners say emergency pull-ins are too far apart
An all-party parliamentary group, chaired by former transport minister Sir Mike Penning, will look at whether smart motorways are more dangerous for drivers than standard motorways.
The group will also look at measures to keep vehicle recovery operators safe across UK roads.
Sir Mike told Sky News: “Why are so many people dying when they come to your rescue on our motorways?
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“If six police officers were killed every year there would be uproar, yet we have six rescue workers being killed every year.”
Vehicle recovery operator Steve Godbold was killed in 2017 whilst attending to a breakdown on the hard shoulder of the M25.
The father-of-four’s partner, Sam Cockerill, told Sky News: “Steve was killed when there was a hard shoulder to operate in. A smart motorway doesn’t even have a hard shoulder so it’s automatically more dangerous.
“Drivers needs to be made more aware about how to be safe, about slowing down and changing lanes when they see a recovery vehicle in action and rescue recovery vehicles should be allowed to have rear red-flashing lights like other emergency services.”
Sam Cockerill's partner Steve Godbold was killed while attending a breakdown on the M25
Larry Axten has been a recovery vehicle operator for nine years. He says working on smart motorways makes him feel vulnerable.
Mr Axten said: “If people don’t actually breakdown in one of the actual slips where they can pull in, it then can cause a major problem because technically we are then in a live lane.
“You’ve still got traffic coming behind, so the car’s in danger itself and unless [the lane has] been shut off you’re in danger as well.”
Highways England told Sky News: “Smart motorways are good for drivers… and evidence proves they are as safe as traditional motorways, which are already among the safest roads in the world.”
But in its own study, Highways England found that driver behaviour might be making smart motorways even more dangerous than they should be.
Many motorists are accused of ignoring the warning signs above lanes
Electronic motorway signs display a red cross above a lane that needs to close because of an obstruction.
But Highways England own study found that one in five drivers ignored the red cross which has led to major vehicle-recovery firms calling for this urgent inquiry into smart motorways safety.
Richard Goddard, managing director of Automania Vehicle Recovery, said: “When I send my guys out, myself and their families expect them to come home.
“What we’re asking for is nothing economic, it’s common sense; better safety, better visibility, better protection for ourselves and the people we’re going out to serve.”