Tired drivers falling asleep at the wheel of their vehicles are becoming a major safety problem, a sheriff has warned.

Speaking at a fatal accident inquiry in Perth, Sheriff James Tierney said he had presided over several cases of accidents being caused by exhaustion in the past year.

The inquiry had heard that van driver Allan Preston, 27, from Wishaw, North Lanarkshire, may have fallen asleep because of the amount of work he was asked to carry out.

He had been working a 10-hour shift during which he drove over 500 miles for Yorkshire-based Driver Hire Nationwide.

No witnesses

His vehicle had swerved across the road into the path of a car driven by Ronald Grant, 68, from Lewis in the Western Isles, on the A9 near Dalguise in Perthshire, killing both of them.

The sheriff said he could not rule that tiredness was to blame because no witnesses had survived.

But his experience in other cases, along with reports in the media and public statements by senior police officers, suggested that it was a matter for concern.

The sheriff said regulations about commercial drivers' hours were tighter in the European Community than in the UK.

Under review

He said a large number of smaller vehicles were still subject to domestic rules, which have not been changed since 1968.

Sheriff Tierney added that it was for the Secretary of State for Transport to decide whether the rules in the UK should be changed.

They are currently under review.

The sheriff formally found that both men had died as a result of injuries sustained in the accident on 13 February last year.