The A40 Westway is due to close for more than a month in both directions in order to carry out essential maintenance works from this week, TfL has confirmed.
The flyover link road, which typically handles more than 95,000 vehicles a day, will be closed to traffic for a period of five weeks starting this weekend.
Since January, the eastbound carriageway of the A-road has been routinely closed each weekend as part of the remedial works.
However the next phase of the project, starting on March 20, requires the entire 2.5 mile link to be cleared of traffic for an extended period, starting from 10pm on Friday until late April.
Built in the late 1960s, the elevated carriageway is reaching the end of its design life and requires urgent restoration to keep it running.
Critical works to the structure include the replacement of two joints which allow the road to expand and contract with changing temperatures.
While timed to coincide with the Easter period, during which traffic levels are typically lower, TfL acknowledged the closure would have a significant impact, with buses likely to be delayed and severe disruption for traffic on nearby roads, particularly at rush hour times.
A total of 33 bus services are due to be re-routed to avoid the section between the Marylebone flyover and the White City.
Weekend westbound closures will also take place from late April to June between Paddington and White City.
Stuart Harvey, TfL’s Chief Capital Officer, said: ‘The A40 is a key artery in west London and it’s vital that we ensure it is well maintained for the tens of thousands of people who use it each day.
‘This essential work will allow the flyover to continue to be used safely for decades to come. I’d like to thank people in the area for their patience during these works and would encourage everyone to plan ahead for any journeys in the area, using alternative modes of transport where possible.’