The drink-drive limit in Scotland will be lowered "as a priority", the Scottish government has said.
Justice Secretary Kenny MacAskill said plans to lower the limit from 80mg of alcohol per 100ml of blood to 50mg will be brought forward later this year.
He said it was intended the change would take effect as soon as possible.
The power to change the limit was handed to Holyrood under the 2012 Scotland Act, which recently received royal assent.
Last week, Scotland became the first part of the UK to introduce a minimum price for a unit of alcohol.
Mr MacAskill said: "The Scottish government has long called for a reduction in the drink-driving limit to 50mg.
"We strongly believe that reducing the drink-driving limit will save lives, and evidence from across Europe shows that alcohol-related road deaths drop dramatically where the limit has been reduced."
Scottish Liberal Democrat leader Willie Rennie had earlier urged ministers to make use of the new powers as soon as possible.
He said: "The new powers devolved under the Scotland Bill present us with some fantastic opportunities to shape the Scotland we want to live in."
Scottish Labour's justice spokesman Lewis Macdonald said: "This a welcome development and something I called for several weeks ago, so I am delighted that the Scottish government are in listening mode.
"We need to get the details right, but the SNP will have our support on the issue as the Scottish Parliament works through the fine print."
Scottish Conservative deputy leader Jackson Carlaw welcomed the proposals.
He said: "We believe that everything should be done to reduce road deaths caused directly by alcohol."
The limit in England and Wales would remain at 80mg of alcohol per 100ml of blood.
The Republic of Ireland lowered the limits last year sparking calls for Northern Ireland to follow suit.
Northern Ireland's Environment Minister Alex Attwood said he hoped to bring in legislation to introduce lower blood alcohol concentration levels for drivers by the autumn.
The blood alcohol limit in the Irish Republic dropped from 80mg per 100ml to 20mg per 100ml for learner drivers, newly qualified drivers and professional drivers.
The limit for all other drivers went down from 80mg/100ml to 50mg/100ml.
The 50mg/100ml applies in several European countries, including France, Germany, Italy, the Netherlands and Spain. Some of the countries have variations, with newly-qualified drivers in Spain having a lower limit.
Campaigners said the Scottish plan was a step in the right direction but a zero-tolerance approach remained their ultimate aim.
Sarah Fatica, general manager at Brake, the road safety charity, said: "A 50mg limit does still leave some level of confusion for the general public about what is safe."
Ms Fatica said she would ultimately welcome a limit of 20mg or less, saying the "best message" to send out was one of zero tolerance for driving after drinking.
Carole Whittingham, spokeswoman for the Campaign against Drinking and Driving, said she was behind the Scottish government 100% but also called for a lower limit to be brought in in the future.
"I'm so glad to hear that somebody is actually grasping the nettle at last," she said.
"Scotland has highlighted that they've got a problem. I just wish that the Westminster Government would do the same."
Justice Secretary Kenny MacAskill said plans to lower the limit from 80mg of alcohol per 100ml of blood to 50mg will be brought forward later this year.
He said it was intended the change would take effect as soon as possible.
The power to change the limit was handed to Holyrood under the 2012 Scotland Act, which recently received royal assent.
Last week, Scotland became the first part of the UK to introduce a minimum price for a unit of alcohol.
Mr MacAskill said: "The Scottish government has long called for a reduction in the drink-driving limit to 50mg.
"We strongly believe that reducing the drink-driving limit will save lives, and evidence from across Europe shows that alcohol-related road deaths drop dramatically where the limit has been reduced."
Scottish Liberal Democrat leader Willie Rennie had earlier urged ministers to make use of the new powers as soon as possible.
He said: "The new powers devolved under the Scotland Bill present us with some fantastic opportunities to shape the Scotland we want to live in."
Scottish Labour's justice spokesman Lewis Macdonald said: "This a welcome development and something I called for several weeks ago, so I am delighted that the Scottish government are in listening mode.
"We need to get the details right, but the SNP will have our support on the issue as the Scottish Parliament works through the fine print."
Scottish Conservative deputy leader Jackson Carlaw welcomed the proposals.
He said: "We believe that everything should be done to reduce road deaths caused directly by alcohol."
The limit in England and Wales would remain at 80mg of alcohol per 100ml of blood.
The Republic of Ireland lowered the limits last year sparking calls for Northern Ireland to follow suit.
Northern Ireland's Environment Minister Alex Attwood said he hoped to bring in legislation to introduce lower blood alcohol concentration levels for drivers by the autumn.
The blood alcohol limit in the Irish Republic dropped from 80mg per 100ml to 20mg per 100ml for learner drivers, newly qualified drivers and professional drivers.
The limit for all other drivers went down from 80mg/100ml to 50mg/100ml.
The 50mg/100ml applies in several European countries, including France, Germany, Italy, the Netherlands and Spain. Some of the countries have variations, with newly-qualified drivers in Spain having a lower limit.
Campaigners said the Scottish plan was a step in the right direction but a zero-tolerance approach remained their ultimate aim.
Sarah Fatica, general manager at Brake, the road safety charity, said: "A 50mg limit does still leave some level of confusion for the general public about what is safe."
Ms Fatica said she would ultimately welcome a limit of 20mg or less, saying the "best message" to send out was one of zero tolerance for driving after drinking.
Carole Whittingham, spokeswoman for the Campaign against Drinking and Driving, said she was behind the Scottish government 100% but also called for a lower limit to be brought in in the future.
"I'm so glad to hear that somebody is actually grasping the nettle at last," she said.
"Scotland has highlighted that they've got a problem. I just wish that the Westminster Government would do the same."
