Latest: Scottish transport minister apologises after motorists stranded overnight

Latest: Scotland's transport minister has apologised after more than 200 motorists were stranded overnight on the M74 as heavy snow and ice caused treacherous driving conditions.

Update 1.10pm: Scotland's transport minister has apologised after more than 200 motorists were stranded overnight on the M74 as heavy snow and ice caused treacherous driving conditions.

Dozens of schools have been closed in parts of Scotland, while public transport has been disrupted by the weather.