Ministers say using the hard shoulder offers a greener alternative
Transport Secretary Geoff Hoon has suggested plans to widen the M6, M1, M62 and M25 will be dropped.
He said a trial on the M42, using the hard shoulder at busy times, had shown it was possible to ease congestion without concreting over more land.
Mr Hoon told Sky News it also meant increasing capacity without the "difficulty and expense" of widening.
He announced plans to roll out use of the hard shoulder across the core motorway network on Thursday.
The Observer reported that plans to widen more than 220 miles of the M6, M1, M62 and M25 had been scrapped in a £5bn cost-cutting exercise.
Asked about the story, Mr Hoon did not deny it, but told Sky News: "What we're proposing is to use the hard shoulder on a number of our motorways in order to relieve congestion at peak times."
He said the M42 trial near Birmingham Airport had proved successful, adding: "The whole point of this is to recognise that we do need more space on our motorways, but we don't necessarily need it all the time.
"We need it at peak times when there's particular problems with congestion.
"Using the hard shoulder, with some quite sophisticated electronic equipment, does allow us to relieve congestion at peak times without necessarily going to the difficulty and expense, and indeed the environmental consequences, of motorway widening."
The hard shoulder scheme trialled near Birmingham sees the lane opened to traffic at peak times, with a maximum speed limit of 60 mph.
But AA spokesman Paul Watters said it would only address "short term congestion" and it would make more sense to widen the motorways now and, if necessary, introduce hard shoulder running later.
"It is road widening on the cheap because the only reason we are going for active traffic management is because it's cheaper than road widening.
"We're concerned [the government] appears to have all its eggs in one basket."
In a document published by the Department for Transport on Thursday, the government said it intended to start "hard shoulder running" on sections of the M6 around Birmingham, the M1 east of Sheffield, the M62 in Manchester and from Bradford to Leeds and the M60 around Manchester, between 2010 and 2012.
Work to allow further sections of the motorways, and of the M3, M25 and M4, to use the hard shoulder would begin by 2015.
It added: "For the sections where we had previously been considering motorway widening, we were able to compare this directly with HSR [hard shoulder running].
"This more detailed work suggests that in all cases where there was originally a proposed widening solution, HSR would provide a feasible alternative."