Stewart Stevenson has resigned as Scotland's transport minister after criticism of his handling of travel chaos caused by extreme weather last week.

He said in a letter to First Minister Alex Salmond: "Although we put in place significant efforts to tackle the event, I feel that I could have done much more to ensure that members of the public who were caught up in a difficult and frightening set of circumstances were better informed of the situation.

"I deeply regret that and for that reason I feel I should step down."

Mr Salmond said he accepted the resignation "with great regret" in a written response, saying: "I understand your reasons for resigning but frankly I think it is wrong that you should have faced this situation.

"You have worked to ensure the preparedness of our transport network for winter weather. These plans have generally proved effective but on Monday we were faced by an unprecedented challenge."

Snow and ice brought much of Scotland to a standstill with traffic gridlock on busy motorways earlier this week.

The Banff and Buchan MSP apologised for a lack of preparation and on Thursday night met with the leader of the SNP government when he told him that he felt he should resign.

He wrote to Mr Salmond: "You kindly asked me to take Friday to consider whether that was the appropriate action to take. I took that time to think this through and I have decided to resign."

The First Minister will announce on Sunday who will assume Mr Stevenson's responsibilities for Transport, Infrastructure and Climate Change.