On each trip they switch between autonomous and manual driving, being controlled by computer across the Forth Road Bridge, and from the M90 and M8 to the A720 in Edinburgh.

Daniel's car eventually crashed on an off ramp of the M8 in the Port Dundas area.

The M8 saw long traffic jams and two of the main routes south - the M74 and A68 - were closed for a time due to accidents.

Mr Henry said particular incidents had impacted the M8 near Livingston and the M74 at various points on Saturday.

The eastbound carriageway of the M8 was closed for around 12 hours to allow investigations to be carried out at the scene.