A FOG detector could be installed at the location of a fatal pile-up on the M40 that involved almost 40 vehicles.

Coroner Darren Salter will ask Highways England to investigate installing the device following an inquest yesterday at Oxford Coroner’s Court into the death of Robert Pilott.

The 64-year-old was the only fatality of the 38-vehicle crash on the northbound carriageway between junction 9 and 10 at about 7.45am on February 14.

It came 24 years to the day after a man was killed in a crash in thick fog just 500 metres south of the February incident.

At the inquest yesterday, Mr Salter returned a conclusion of accidental death and noted there had been “extremely dense and very localised fog” in the area.

In witness statements read out at the inquest, several drivers of other vehicles involved in the crash said a thick bank of fog had appeared suddenly in front of them.

Isabelle Le Breton, who was driving a blue Hyundai Getz, said: “It was like having a sheet of plastic pulled in front of you.”

Robert Galbraith, who was driving his wife’s black Vauxhall Astra, said: “ I had never seen fog like it in my life.”

Collision investigator Terry Anderson, giving evidence at the inquest, said the pile-up had begun when a Vauxhall Corsa and a Ford Mondeo collided 30 or 40 metres ahead of the main incident.

He added there was a possibility some drivers had not had their fog lights on because their main headlights were set to automatic but were not triggered by fog in daylight.

Mr Pilott, from Woking in Surrey, was the front-seat passenger in a red Ford Fiesta driven by his wife Susan.

He suffered a broken neck after the vehicle crashed into the crash barrier of the central reservation.

After returning the conclusion of accidental death, Mr Salter said he had no criticism of Highways England but wanted to write to the agency about two issues.

He said: “I want to ask if there is a firm process for fog signs being illuminated and how this info goes in to the control room.

“Secondly, at this particular location there was no fog detector.

“I have no criticism of that because at most locations there will not be one.

“But one was in place at a different location were there was a known history and data [of fog].

“At this particular location [between junctions 9 and 10] there is no long history of problems.”

Mr Salter stressed he was not explicitly recommending one, but wanted Highways England to examine the possibility.

The only fog detector on the M40 is at junction 15 near Warwick.

The devices alert highway staff to fog, enabling them to trigger electronic warning signs.