Highways England could be charged with manslaughter following the death of a 62-year-old woman on a stretch of smart motorway.
A coroner investigating the death has said she may refer the case to the Crown Prosecution Service to consider if the charges are appropriate.
Nargis Begum, from Sheffield, was killed on the M1 in South Yorkshire in September 2018 when another vehicle collided with her husband’s Nissan Qashqai, which had broken down.
Begum had exited the Nissan, which was stranded in a live lane, and was waiting for help when the incident happened.
The smart motorway section had no hard shoulder.
More than 16 minutes elapsed between the Nissan breaking down and the collision, plus a further six minutes before warning signs telling other drivers not to use the lane in which the Nissan was located were activated.
At a pre-inquest review Mundy said: "I want to know why, essentially, it's as simple as that."
The case, at Doncaster Coroner's Court, was adjourned until February 11 to allow Government lawyers time to prepare a response
The CPS has decided against prosecuting the driver who hit the Nissan.
Mundy added that she was also considering whether to refer this decision back to the CPS based on the evidence she had seen.
In March, the Government announced a series of measures to improve the safety of smart motorways, following a review commissioned by Transport Secretary Grant Shapps.
Analysis commissioned by the Transport Secretary reportedly found that "in most ways", smart motorways are as safe as, or safer than, conventional ones.
There was also an admission that some risks are higher than on conventional motorways, for example the risk of a collision between a moving and stationary vehicle.