Motorists would be penalised for driving into Scotland's cities unless their vehicles have the cleanest engines, plans for the first low emission zones (LEZ) today showed.
Other vehicles would be banned, with penalty levels expected to be more than £20 a day.
The RAC said these would include most diesel cars, since the latest engines were only introduced three years ago.
That would be ten times the proposed £2 a day congestion charge proposed for Edinburgh 15 years ago.
Glasgow city centre is expected to be first zone, to be launched by the end of the year.
Edinburgh - which is also bidding to be first - along with Aberdeen and Dundee would follow by 2020.
Environmental campaigners urged the Scottish Government to get a move on with the scheme to tackle the country's air pollution hotspots as transport minister Humza Yousaf launched a two-month consultation into what it might involve.
First Minister Nicola Sturgeon said today the first LEZ would be announced shortly as she launched a £60 million fund to accelerate electric vehicle charging and battery technology.
She said air pollution in some areas of Glasgow were "really bad".
The only maps in the consultation document are of Glasgow city centre, some of them show streets where pollution limits are broken, such as parts of Argyle Street, Union Street, Renfield Street, Hope Street, St Vincent Street and Renfrew Street.
The document said: "The Scottish Government’s preference would be a road access restriction scheme for LEZs."
This is where vehicles that do not meet emission standards (or are not exempt) would incur a penalty if they entered a LEZ.
Possible penalty levels were not included in the document, but it said it would be "proportionally higher" than in LEZs in other countries where drivers of vehicles not meeting emission standards were charged less than £20 a day.
The proposed standards are Euro 4 petrol engines, introduced in 2005, and Euro 6 diesel engines for cars, taxis and vans, introduced in 2014.
Bus and lorry engines would have to be Euro VI standard, and motorbikes Euro 3.
The zones would operate round the clock and be enforced using cameras recording vehicle number plates.
There could be exemptions for blue bade holders, emergency vehicles, bin lorries, and night shift workers travelling when no public transport was available.
RAC spokesman Nicholas Lyes said: “These proposals will have motorists reeling at the thought that they could be banned from driving in certain areas of Glasgow, Edinburgh, Aberdeen and Dundee possibly as early as next year if they drive a diesel vehicle that is registered prior to September 2014.
"If they flout the ban, drivers in the wrong vehicles could face a costly fine.
“Nobody doubts the need for bold decisions being made to tackle Scotland’s pollution issue in its biggest cities, however, the outlined measures could have serious financial and practical impacts on those living and working in and around these cities.
“Unlike the London Ultra-Low Emission Zone, where motorists and businesses will have had up to six years to plan and budget for necessary upgrades to their vehicles, these proposals appear to fast-track stringent restrictions with a limited ‘sunset’ or grace period for those who live or operate businesses within the proposed zones.”
“Motorists accept that tough measures are essential to tackle our air quality problem however there should not be a rush to penalise them at the first opportunity.
"Focus should firstly be on establishing which vehicles are the highest polluting vehicles doing the most mileage in the most polluted areas.
"Typically in urban area these tend to be buses and taxis so there must be an urgency to clean these vehicles up first.”
Neil Greig, policy and research director of the IAM RoadSmart motoring group, said: "Specifying Euro 6 for diesel is very stringent as it is the latest standard.
"In effect this could bank relatively new cars from Scottish cities. This will hit low income families worst."
Ms Sturgeon admitted the plans could be unpopular.
She said: "Some of the changes that will be involved for a low emission zone.. do involve behavioural change, they do involve things that can be difficult for people.
"But the scale of this challenge and the importance of this challenge means we've got to do these things.
"But if we get ahead of the game in Scotland there's also lots of benefits we can get out of this transition.
"We can encourage businesses to come here and do their research and make their products.
Scottish Greens environment spokesman Mark Ruskell urged ministers to "pick up the pace" on the plans.
He said there were 38 pollution zones in Scotland where safety standards are regularly broken, including Bearsden, Glasgow, Johnstone, Coatbridge, Crieff, Cambuslang, Linlithgow, Edinburgh, Musselburgh, Falkirk, Dunfermline, Dundee, Perth, Aberdeen and Inverness.
Mr Ruskell said: “Traffic pollution causes lung and heart disease, and thousands of premature deaths every year in Scotland, so the fact the Scottish Government is slowly waking up to the need for action shows the benefit of consistent Green pressure on this issue.
"We now need a commitment to fund LEZs with local councils, given we have 38 pollution hotspots in communities across the country."
Emilia Hanna, air pollution campaigner for Friends of the earth Scotland, said: “The Scottish Government last year made a commitment to introduce the first LEZ by 2018, but needs to announce the location of that zone as soon as possible if it is to have a chance of being delivered on time.
"The obvious place for the first LEZ is Glasgow, because it has the highest death toll from air pollution, with over 300 people dying early from toxic air each year.”
Mr Yousaf said: “We have a clear vision for Scotland’s air quality to be the best in Europe.
"However, poor air quality remains a public health issue, particularly for those with existing respiratory and cardiovascular conditions.
“This consultation will help us deliver LEZs that are well designed with consistent national standards, in partnership with local authorities and regional transport partnerships.
"LEZs allow local authorities to set an environmental limit on key transport routes to improve air quality by allowing access to only the cleanest vehicles.
“As well as improving air quality, low emission zones can also contribute to tackling congestion and improve our urban environments.
“The vehicles to be included in, or be exempt from, LEZs will be for individual local authorities to decide, but could include freight, taxis, buses and private motor vehicles.
"The consultation also seeks views on issues such as lead-in times, operating hours and enforcement."
The first LEZ was introduced in Sweden in 1996 and there are now more than 250 in 15 European countries.
A spokesman for the Scottish Government's Transport Scotland agency said: “Only when city-specific LEZs are set up, and the vehicle types are decided upon by local authorities, will we know for certain how may vehicles would be affected.”