Most of the London bus network was suspended
The Mayor of London, Boris Johnson, has been blamed by a committee of MPs for a "lack of leadership" during February's snow chaos in the capital.
The disruption to London transport was "unsatisfactory" and better planning is needed in future, a report has found.
In particular, there needs to be better co-ordination between local authorities and bus and train operators, the Transport Select Committee said.
Mr Johnson said putting buses on icy roads would have been "irresponsible".
The committee conceded that "many factors made disruption unavoidable".
Thousands of people were unable to travel in London on 2 February as snow disrupted the city's transport network.
Most London buses were suspended, more than 260 schools were closed and at one point both runways at Heathrow airport were out of operation.
The cross-party group of MPs found that rather than extra resources, "co-ordination, prioritisation and visible leadership" were the most important factors in ensuring transport can recover quickly.
It recommended local authorities should "identify weaknesses in their emergency plans" and there be "high priority to clearing access routes for emergency services".
Committee Chairman Louise Ellman MP said: "The travel disruption at the beginning of February was unsatisfactory.
"While the unusually heavy snow fall meant that some disruption was inevitable, it is vital that all those involved ensure that winter maintenance plans and crisis responses are reconsidered so as to minimise disruption in the future."
She added that "strong co-ordination" and "visible leadership" are crucial to responding to severe weather.
Ms Ellman said: "More active strategic leadership from Mayor Johnson and more practical effort on his part to oversee preparations for a rare but forecast event, could have given the public far more confidence and might have ensured public transport services were restored much more quickly."
But Mr Johnson branded the committee's report as "partisan and wholly opportunistic".
The Mayor's spokesman said: "With the benefit of hindsight it is even clearer to the Mayor that putting buses on icy roads, which could not be cleared, would have been irresponsible, dangerous and potentially lethal.
Lessons to learn
"The Mayor is pleased that today we are arguing over a select committee report, rather than giving evidence at an inquest into why Londoners have been injured unnecessarily on the icy roads."
A Department for Transport spokesperson said: "We welcome the committee's report which we will respond to in detail once we have considered it fully.
"Transport Secretary Geoff Hoon has already asked the UK Roads Liaison Group to review what lessons can be learned from this year's severe winter and recommend how we can be even better prepared in the future.
"Its review will include examining the supply and distribution of salt, exploring the need for a national salt reserve and considering whether changes should be made to the code of practice for highway maintenance.
"Mr Hoon has asked the group to report back by the summer and we will present the conclusions to Parliament."