A 69-year-old Maserati driver who pulled out to overtake and narrowly missed an oncoming motorcyclist in Snowdonia, North Wales, has failed to get a dangerous driving conviction overturned.

A court heard that if it had been anything but a motorbike approaching then there would have been a catastrophic head on collision.

But the rider, who had never been traced, had been able to squeeze through.

Michael William Roberts denied driving the Maserati Gran Turismo dangerously but was convicted by Caernarfon magistrates in May of last year.

His appeal against the conviction at Mold Crown Court was rejected on Friday.

The court heard that he pulled out to overtake on the A4212 Trawsfynydd to Bala Road as he made his way from Porthmadog to Shrewsbury on October 15, 2017.

But there was a near miss with a motorcyclist - who had never been traced - coming the other way.

Mr Recorder John Philpotts, sitting with two magistrates, dismissed his appeal and said that Roberts overtook a Honda on the approach to a blind right hand bend.

A motorcycle appeared, which was not being ridden at an excessive speed.

He said that having pulled out to overtake, Roberts had been unable to regain the correct side of the carriageway.

"His vehicle and the the motorcycle were approaching each other at a high closing speed," he said.

Fortunately, the motorcyclist was able to ride through a very narrow gap between the Maserati and the verge, avoiding "a catastrophic collision."

But Mr Philpotts said that if the on-coming vehicle had been a car, van or lorry rather than a motorcycle then a head-on collision would have been inevitable.

No attempt had been made by Roberts to brake or to try and avoid a potential collision.

He then proceeded to overtake three vehicles ahead of him on the approach to a bend but Mr Philpotts said that nothing turned on that.

The court had heard evidence from a driver who was overtaken that in his judgement that had been a perfectly reasonable thing to do.

He said the court had the advantage of viewing "real evidence" via dash cam footage from the vehicle which was first overtaken.

It was Roberts' case that the manoeuvre was safe and that he could have returned to the correct side of the carriageway had the vehicle he overtook not accelerated and if another vehicle in front had not braked or slowed - which meant the gap he intended to drive to had been reduced.

But the evidence showed that the driver who was overtaken had already started to accelerate before Roberts' overtaking manoeuvre commenced.

He had abandoned the idea of overtaking himself because of the approaching motorcycle.

Be that as it may, Roberts should have allowed for all eventualities before embarking upon the overtaking manoeuvre, the Recorder said.

The gap that was available was clearly too narrow to be safe in all the circumstances, he said.

"In our judgement his driving was clearly dangerous at the relevant time."

The incident must have been terrifying for the motorcyclist, he said.

He said that the margin for error must have been very small indeed.

"It is a matter of the greatest good fortune that there was not a collision," he explained.

Prosecuting barrister Karl Scholz said that Roberts of Aldersgate Street, London, had been ordered to pay fines and costs totalling £2,425 by the magistrates.

He was banned from driving for a year and ordered to take an extended driving test.

The Recorder said that the penalties would stand and that he would have to pay an additional £620 towards the costs of the appeal.

Car driver Sean Taylor told the court he saw Roberts pull out to check the road ahead on several occasions. But the first he knew of his overtaking manoeuvre was when he was alongside his Honda vehicle.

The dash cam footage which was played to the court showed the blue Maserati on the wrong side of the road as the motorcycle approached, narrowly missing it.

The rider was seen to raise his hand as the two vehicles passed.

Roberts momentarily pulled into the left hand side before overtaking other three vehicles.

In evidence, Roberts, who said he had been driving for 50 years and had a clean driving licence, knew the capability of the car and decided it was safe to overtake.

There was a gap ahead but it closed when he claimed the car he was overtaken accelerated and the car ahead slowed down.

When he began the manoeuvre, the motorbike was not in sight, he said, and suggested the biker was riding at a high speed.

Expert evidence was called by both prosecution and the defence.

Defending barrister Benjamin Waidhofer initially made a submission that there was no case to answer and claimed the only possible criticism of his client was that he should have had the telepathic ability to look through trees and see the motorcycle approach before the bend in the road. But that application was rejected.

Mr Scholz said that it was the prosecution case that the defendant simply should not have overtaken in the circumstances and to do so was dangerous.