Costain has completed critical works on the A40 Westway Structures Refurbishment project extending the life of the asset by 50 years in one section. 

Work on the A40 began in 2024 and focused on the installation of seven expansion joints on a 4.5km stretch between Wood Lane and the Marylebone Flyover, which passes through Kensington and Chelsea, Hammersmith and Fulham and the City of Westminster.

Originally built over half a century ago, the bridge structures that support the carriageway and slip roads are made from reinforced concrete.

As well as the joint replacements, Costain also carried out concrete repairs, resurfacing and other ancillary works on behalf of Transport for London (TfL), intended to improve the reliability and safety of the structures.

The project included the replacement of an ‘operationally critical' roller shutter expansion joint, which the infrastructure solutions company finished in 2022.

Disruption was reduced using off-site construction, which also included the creation of temporary bridging cover plates that ‘mitigated movements caused by changeable weather whilst the joint replacements were carried out'.

Costain also conducted trial installations for each of the new joints at a separate location, which allowed them to complete the installation of the most complex joints while live traffic operated continuously alongside the works.

Further work is planned for 2026, with Costain due to undertake the next package of work on the A40 Westway project, which plans to deliver additional improvements and maintenance upgrades at the Marylebone Flyover and on the A40 Westway.

Emma Curran, senior project manager at Costain, commented: ‘Our upgrades have extended the lifespan of this section of the A40 by more than 50 years, and thanks to our close collaboration with TfL and the application of production-thinking principles, we ensured minimal disruption to residents and road users.'

Charlotte Day, project manager at TfL, said: ‘The A40 Westway is a critical transport artery into the nation's capital that has required essential maintenance works. Costain and its supply chain have worked efficiently and innovatively to replace the joints that will ensure the road can continue to run safely and reliably for years to come. This has all been achieved with the least disruption possible to people using the road and living in the area.'

Image credit: Costain