Questions remain unanswered after a man died in a 'catastrophic' crash in Derbyshire.
Martin Coverley, 44, suffered extensive injuries when the car he was driving left Huthwaite Lane in Blackwell and crashed into a bridge.
Chesterfield coroners' court heard Mr Coverley, of Raven Avenue, Tibshelf, had cannabis in his system which may have affected his cognitive function - but an epileptic seizure could not be ruled out.
Coroner James Newman told today's hearing: "With the press present, I'd like to get across the message that drug-driving is incredibly dangerous - but that's not to say Mr Coverley's death was caused by the use of cannabis. It's a potential factor, it may have had a bearing on his cognitive function.
"Mr Coverley suffered from epilepsy. Could he have had an epileptic seizure? That can't be ruled out.
"For some reason he left the carriageway and for some reason he didn't make any effort to correct it.
"There are questions we can't always answer."
No other vehicles were involved in the crash and nobody witnessed the collision itself.
The incident happened at about 6.40am on April 11 last year.
Mr Coverley, who was on antidepressants, was driving to Nottingham for his first day back at work after a period of absence, the court heard.
Mr Newman said: "There's no evidence before me to say the crash was a deliberate act by Mr Coverley."
He added that the hire controller suffered 'catastrophic' injuries which would have been 'instantly fatal'.
Forensic collision investigator PC Paul Moorcroft told the court: "Mr Coverley's Ford Focus had massive front end damage.
"It's no surprise he suffered the injuries he did."
PC Moorcroft said tests showed there were no mechanical or road defects which would have contributed to or caused the collision.
According to PC Moorcroft, it is more than likely that Mr Coverley, who was wearing a seatbelt, was travelling at 50mph at the time of impact.
Mr Newman concluded that Mr Coverley died as a result of a road traffic collision.