All bendy buses will be phased out by 2011, the mayor has pledged
Mayor of London Boris Johnson's plan to replace bendy buses with Routemasters is misdirected and prohibitively expensive, a report has suggested.
The report for the RAC Foundation said the bendy bus could carry people in larger numbers and quicker.
It also suggested a London-wide road charging scheme and criticised the mayor's focus on cycle schemes.
Kulveer Ranger, the mayor's transport adviser, said the report was "misjudged" and "misdrected".
Mr Johnson previously called bendy buses "writhing whales", saying they were dangerous and enabled fare evasion.
The report also warned that concentration on the 2012 Olympics was threatening to divert engineers away from the needs of the road network.
Commenting on the findings, Professor Stephen Glaister, director of the RAC Foundation, said: "The mayor must show leadership.
"He needs to think less about attention-grabbing policies linked to niche modes of travel like cycling and grasp the bigger problems of transport in the capital, not least congestion in outer London.
"With the best will in the world, encouraging a few more people onto their bikes is not going to solve the relentless jams in the suburbs.
"What might solve it is a London-wide road charging scheme. Not one just focused on the centre."
He added: "The Mayor also needs to rethink plans to re-introduce the Routemaster.
"Whilst there are routes where bendy buses are inappropriate, when it comes to mass transport they carry more people, more quickly than double-deckers ever will.
"And with TfL facing a reported £2 billion budget shortfall there is also the small matter of where the cash is going to come from to pay for these new vehicles."
However Mr Ranger said Mr Johnson wanted to protect and improve the road network for all users.
He said: "Unlike the RAC Foundation, the mayor's focus is not only on drivers.
"He makes no apology at all for pursuing radical measures to increase cycling and walking and greatly enhance our public transport network."