An 85-year-old motorist blindly followed his Sat Nav up the wrong side of a dual carriageway.

Hamish Wedderspoon continued driving in the fast lane of the A9 for a mile as oncoming drivers were forced to swerve out his way to avoid a high-speed crash.

Wedderspoon was banned from driving for three years and fined £5000 at Perth Sheriff Court on Friday.

The trial heard how the incident only came to an end when numerous other drivers stopped and managed to bring traffic on the northbound A9 to a complete standstill.

Sheriff James Macdonald said: "This was in any view a serious instance of bad driving.

"The standard of driving causes concern for public safety. I do not regard the level of dangerousness to be in any way borderline.

"This incident happened because the accused chose to follow a direction given by the Sat Nav in the vehicle, over the obvious view of the road layout which he had.

"There was a decision to adhere to a computerised instruction in preference to the road layout.

"The accused was in a state of disorientation on this journey."

Witness Thomas Brodie told the court he was driving north at 70mph when he became aware of Wedderspoon's 19-year-old VW Golf heading straight at him.

He estimated the pensioner was driving at up to 50mph and ignoring other cars.

He said he "braked harder than he had ever done before" and swerved out of Wedderspoon's way.

Wedderspoon said his driving was careless, and came about when he took a wrong exit from a roundabout as he was heading to Glasgow.

He denied it was dangerous but was found guilty.

Wedderspoon, Somersall Lane, Chesterfield, was found guilty of dangerous driving on the A9 on May 11 last year.

He was ordered to re-sit the extended driving test before returning to the road.