The government has "barely begun" its 10-year masterplan to improve transport, five years after its launch, the Conservatives say.
Overcrowding will get worse and worse, say the Tories
Shadow transport secretary Chris Grayling said this meant ever-longer traffic jams and overcrowded trains.
The Tories have listed 30 pledges they say Labour have failed on or shelved.
Transport Secretary Alistair Darling said a doubling of spending had brought transport improvements, and he accused the opposition of planning cuts.
Mr Grayling said: "The government made promise after promise when it came to power about its plans for the transport system.
"But although there have been some improvements, most of the new projects they promised to complete by 2010 have either been scrapped altogether or kicked into the long grass.
"The result will be longer and longer traffic jams, and ever more crowded trains.
"Their grand schemes have turned out to be a massive disappointment, and their record on transport is a failure which will return to haunt them."
The "broken" pledges included promises to cut congestion, reduce rail overcrowding, launch new freight and tram schemes, and increase cycling.
But Mr Darling said there were a number of areas of progress.
These included fewer deaths and serious injuries on the roads, more people travelling by train than at any time since the 1960s, a third of rolling stock renewed, key railway lines upgraded and more than 100 road schemes completed.
Mr Darling accused the previous Conservative administration of a "woeful" legacy of "spending cuts, poor planning and botched rail privatisation".
"Since 1997 we've doubled transport funding to make up for the years of under-investment and the stop-go spending under the last government.
"Above all else, a transport system needs sustained investment, which is why we have pledged to go on increasing transport spending above inflation for the next decade."
He said new Tory leader David Cameron was committed to spending less on public services than Labour, which he said would mean investment cuts in transport.