The Greater Manchester boroughs of Tameside and Oldham have topped a table of the places in the UK where traffic has grown fastest over the last decade.
The figures compiled by the environmental group the Campaign for Better Transport found that traffic volumes had grown by 38.6% in Tameside, closely followed by Oldham's 34.5% rise.
Politicians in both areas, to the North East of Manchester on the M60 orbital, this summer voted in favour of Greater Manchester's Transport Innovation Fund bid, which could lever in a total investment package of £3bn. Extensive improvements to public transport, including more trams, buses, trains and dedicated yellow school buses, are envisaged ahead of the introduction of a road-pricing system. A decision is due from the Government in the New Year.
Stephen Joseph, executive director of the Campaign for Better Transport, formerly known as Transport 2000, said: "We can't go on like this. Traffic is destroying our communities, our health and our environment."
A study by the Department for Transport predicts that an extra 6m cars will be running on British roads by 2031, a total of 33.5m.