Motoring groups have described plans to charge up to £5 a day to drive into Manchester city centre as another tax on road users.
The Association of British Drivers (ABD) said building more roads was the answer to easing congestion rather than introducing pay-as-you-drive to the city.
And campaign group Safe Speed said drivers faced being "taxed up to the eyeballs" to pay for a system in which it claimed only the technology providers would benefit.
The road-pricing scheme, unveiled by the Association of Greater Manchester Authorities (AGMA), would be the first of its kind in the UK.
It is scheduled to be ready for use by autumn 2012 and would pave the way for similar projects nationwide.
Commuters will have to pay a deposit for an electric tag to be fitted inside their windscreen, which will record their movements along the 15 main routes into the city.
Entering an outer cordon around the M60, encircling the city, would cost £2, with a further levy of £1 to get into the centre.
An extra £1 would be charged to leave each of the zones but motorists who use the roads outside peak times would not pay a penny.
There would be no charges at weekends and no charges on weekdays before 7am, between 9.30am and 4.30pm, and after 6.30pm.
Lord Peter Smith, leader of AGMA, said congestion in the city needed tackling if Manchester was to realise its full economic potential.
