A man suffered “catastrophic” injuries when a van driver who had taken drugs crashed into him on the hard shoulder of the M8 near Harthill.
David Nicolson, 36, has now been warned to expect a prison sentence following the incident on October 17, 2022.
Nicolson, of New Inchinnan Road, Paisley, appeared at Hamilton Sheriff Court.
He admitted causing serious injury to Ryan Docherty by driving dangerously with at least four times the permitted amount of ketamine in his system.
The court heard the victim suffered a brain injury and skull, facial, rib and spinal fractures.
He spent months in hospital undergoing surgery, including facial reconstruction and rehabilitation.
Lewis Devoy, prosecuting, said the crash happened around 3.45pm.
Mr Docherty, a roofer, and two colleagues were returning home after working in Edinburgh.
He was driving the works van westbound and pulled on to the hard shoulder for a toilet stop.
He was standing beside the van when he was hit.
Nicolson was alone in a Renault Traffic van and was also driving west.
Mr Devoy told the court: “The accused allowed his van to drift on to the hard shoulder.
“It collided with the back of the stationary van and also struck Mr Docherty who was propelled into the air for a distance of 15 metres before coming to rest on the carriageway.
“Mr Docherty’s van was pushed up the grass verge with his two passengers inside.
“The accused was not injured.”
Nicolson’s lawyer said the dad-of-two has an “underlying drugs misuse issue” that he has been getting treatment for.
His physical and mental health have deteriorated since the crash.
Sheriff Michael Higgins deferred sentence until next month for background reports and imposed an interim driving ban.
He continued Nicolson’s bail but told him: “Clearly, this has had a catastrophic effect on the complainer.
“A custodial sentence must, in the circumstances, be at the forefront of the court’s mind.”
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