Police yesterday named a young man who died following a two-car collision on the B993 in Aberdeenshire on Saturday as Ian Buchanan, from Aberdeen.
He would have celebrated his 23rd birthday yesterday.
Mr Buchanan was a passenger in a Honda Civic driven by his friend Kris Barr, 23, who is himself "critical but stable" in hospital.
The 51-year-old female driver of a VW Golf was released from hospital yesterday.
Yesterday Lynda Barr, Mr Barr's mother, said: "We are absolutely devastated for Ian's family. Our thoughts and prayers are with them."
Two people were also killed in separate accidents on Sunday evening.
A 19-year-old man died after his Vauxhall Corsa was involved in a head-on collision with a Land Rover Discovery on the A85 near Perth.
The two occupants of the Land Rover were taken to Ninewells Hospital in Dundee after suffering minor injuries.
Meanwhile, a crash between a BMW car and a Land Rover on Halbeath Road, Dunfermline, killed the BMW driver.
A woman is also being treated for spinal injuries following a two-car collision on the Blackburn-Addiewell road in West Lothian yesterday. Another casualty – a man who was in the other car – refused to be taken to hospital by the ambulance.
After the weekend's roads carnage, the parents of a teenager killed in a car crash are backing a campaign to stop young people dying on Scotland's roads.
In March this year, Callum Matheson and Ahlee Jackson, both 17, died after an accident in Inverness.
Mr Matheson's parents, Graham and Diane, want to visit schools to tell pupils about the devastation felt by families as a result of fatal road accidents.
They have also met Highlands and Islands Labour MSP David Stewart who has asked police and Highland and Moray councils to back a campaign to stop young drivers from being killed or seriously injured.
Mr Stewart has suggested the introduction of measures to compel young drivers to display the "P" plate on their vehicle for 90 days after successfully passing their test.
Mr Stewart also wants to see young drivers attend a one-day Pass Plus driving course and a limit on the number and age of young passengers carried by a new driver.
Mr Stewart said: "I hope all the organisations I have contacted and the government will join me and Mrs Matheson in finding answers to this terrible problem. Hopefully, by working together, we can find the right solutions."
In a statement, Mr and Mrs Matheson said: "We have asked Mr Stewart to help investigate the measures other countries have in place to reduce the deaths of young drivers and their passengers."