Hammersmith Bridge will to close to all traffic over half-term, spelling delays for motorists and bus passengers on either side of the river.
The closure from Feb 13 to 22 will allow Hammersmith and Fulham and Richmond councils to install new crossings, paving and bus barriers on the north and south ends of the bridge.
It will mean traffic will be diverted to Putney Bridge and spells delays for drivers and bus passengers on all routes using the bridge.
Pedestrians and cyclists will still be able to cross despite the road works.
H&F Town Hall says the much-needed works will improve traffic flow and have been scheduled during half-term to cause minimal disruption to traffic.
Cabinet member, cllr Nicholas Botterill, said: "These road works are vital to free up the movement of traffic exiting Hammersmith gyratory and will help imporve north-south traffic flows.
"While there will be inevitable disruption in the short term, in the long term the works will free up our congested roads making a vast difference to all road users."
Critics say the closure is badly times, as Albert Bridge is also closed meaning traffic will bottleneck in Putney and alternative routes across the river.
Andrew Slaughter, Labour MP for Ealing, Acton and Shepherd's Bush, says the works should have been completed the last time the bridge was closed a few years ago,
"People can not understand why they're doing it at the same time as other bridges are closed. It looks like bungling."
The closure starts at 5am on Feb 13.
