TfL to Close A40 Westway for Safety-Critical Marylebone Flyover Joint Replacements

Transport for London (TfL) has announced a temporary full closure of the A40 Westway between the Westway roundabout and the Marylebone flyover from 20 March until late April 2026.

The closure is necessary to replace two expansion joints on the flyover, which have reached the end of their service life.

Expansion joints allow the structure to expand and contract with traffic and temperature changes, and the complex nature of the work means the carriageway cannot remain open during the replacement.

BackgroundThe closure is part of a multi-year Westway renewal programme, with Costain – appointed in 2020 – delivering the works. The elevated section and slip roads in this area are supported by approximately 21 reinforced-concrete bridge structures, originally built in 1969–70, some of which are now approaching the end of their serviceable lives.

Works completed so far:

• Phase 1 (summer 2022): Replacement of an operational roller-shutter expansion joint.

• Phase 2 (2024–2025): Replacement of 10 tooth/comb joints, parapet protection, targeted resurfacing, concrete repairs, and expansion-joint replacements on slip roads and three additional joints on the A40.

• Phase 3 (20 March 2026): Replacement of two Marylebone flyover expansion joints.

The A40 Westway carries up to 96,000 vehicles per day, making it one of TfL’s busiest strategic routes. To reduce disruption, the closure has been scheduled partly over the Easter period, when traffic volumes are typically lighter.

Traffic management and public transportTfL will implement a full carriageway closure, with official diversion routes signposted. Local roads and diversion routes are expected to be busy, and journey times may be significantly longer. A traffic-signal strategy across the surrounding network will be used and continuously reviewed throughout the closure.

Impact on buses:TfL warned that 33 bus routes will be affected, though detailed service changes have not yet been published.

TfL statementStuart 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.”

TfL advised drivers and commuters to plan ahead, consider alternative routes or modes of travel, and expect delays. Further works on the Westway are planned, but dates have not yet been confirmed.