A drug-driver reached speeds of 100mph on the A55 dual carriageway and at one stage tried to overtake a vehicle ahead of him in the outside lane.
David Blunt lost control and spun across the carriageway, ending up on the nearside verge.
Mold Crown Court heard yesterday he wanted to get away because he was on a suspended prison sentence.
His overtaking manoeuvre was branded as “stupid” by a crown court judge.
Mr Recorder Timothy Petts said it was fortunate he had not killed himself or other road users.
Blunt, 32, was jailed for a total of 12 months after he admitted dangerous driving, driving with cocaine in his system and being in breach of a previously suspended prison sentence.
He was banned from driving for two-and-a-half years and was ordered to take an extended driving test.
Mr Petts said the A55 was one of the principal roads in North Wales and Blunt had driven at more than 100mph which was “very dangerous”.
Mr Petts told him: “You are very fortunate that no-one was injured or killed, including yourself.”
The overtaking manoeuvre had been stupid, he said, and occurred at a time when he had controlled drugs in his system.
Barrister Frances Willmott, prosecuting, told the court an off-duty police officer followed Blunty’s vehicle.
The car was said to have reached 100mph travelling west. Blunt came up behind two vehicles – one in each lane – between Caerwys and the Rhuallt Hill.
But he tried to overtake the vehicle in the outside lane, going onto the area between the road and the central reservation.
He lost control and span across the road in front of both vehicles.
It flipped over a fence on the left side of the carriageway and ended up on the verge.
Blunt, she said, got out of the car and then tried to get back in again.
He punched the windscreen injuring himself, and was arrested.
Blunt wanted to get away because he predicted he would go to prison – and was in breach of a suspended sentence.
Barrister Sarah Yates, defending, said Blunt estimated his speed at more like 85mph.The cocaine in his system had come from his use of the drug the previous night.
He had not intended to drive but had received a message from his partner that there was a violent incident going on and he wanted to get home as quickly as possible.
The court heard Blunt, of Primrose Hill, St George, near Abergele, had more than 200 microgrammes of cocaine in his blood compared with the legal limit of 50.
He received an eight-month prison sentence for dangerous driving and a concurrent two-month sentence for drug driving.
Four months of the suspended sentence was activated consecutively, making 12 months in all.
A spokesman for the North Wales Police Eastern Roads Policing Unit said after the hearing: “David Blunt committed an appalling act of dangerous driving while under the influence of drugs and it was only by good fortune no-one was seriously injured or worse.
“While attempting an overtake on the busy A55 near St Asaph he lost control of his vehicle and crashed, sustaining serious injuries himself.
“Cases like this demonstrate the huge risks taken by those who drive while under the influence of drugs and their total disregard for other road users and so it’s reassuring to see a custodial sentence imposed.
”We welcome the outcome and hope it will provide the public with reassurance, make our roads safer and demonstrate North Wales Police will relentlessly pursue those who breach the #fatal5.”