A lorry driver is likely to have suffered a blackout in a crash which killed a Borders Railway construction worker, a sheriff has concluded.
Huw Jenkins, 54, died after an HGV driven by John Boyes, 75, hit his tractor on the A7 near Galashiels.
His death was the subject of a fatal accident inquiry (FAI) at Selkirk Sheriff Court earlier this year.
Sheriff Michael Wood ruled that no reasonable precautions could have prevented the accident.
The FAI heard that Mr Boyes, who has since died, appeared confused and had no idea what had happened when spoken to by police officers.
But he had driven the lorry for about a mile afterwards negotiating bends and parked vehicles before bringing his lorry to a halt.
This led the sheriff to believe Mr Boyes could have suffered a temporary loss of consciousness but made a full recovery.
In his determination, he said medical evidence was unable to provide an explanation although the inquiry heard Mr Boyes suffered another loss of consciousness two months after the accident.
Sheriff Wood stated: "Faced with such medical uncertainty it is difficult to reach any conclusion other than that such evidence was adduced of Mr Boyes' appearance and condition immediately after the accident is consistent with his having suffered transient loss of consciousness while driving.
"The extent of the loss could not be established and it is possible that, as was reported by his wife on 19 July he was "on and off" which might explain the lorry being driven for the post accident mile."
The accident happened on May 1 2014, while Mr Jenkins, from Tonmawr, near Neath, in South Wales, was working on the Borders Railway construction.
Mr Boyes, of Newton-on-Mill, near Hawick, died in August 2014.