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Costain appointed to deliver major London road upgrade

A40 highway underpass at night

28 September 2023

Transport for London (TfL) has commissioned infrastructure solutions company, Costain, to provide detailed design and construction services for the second phase of improvements to the A40, one of London’s key east-west arteries.

The upgrades will improve the safety and quality of customer journeys through this section of the road, which is used by 96,000 vehicles per day. Targeted interventions include the replacement of six cantilever expansion joints, new measures to protect parapets in high-risk locations, and resurfacing and concrete repairs on an approximately two-kilometre section of road. The plans will focus on minimising inconvenience to road users, with works expected to be completed by summer 2025.

Andy Clarke, Director for Integrated Transport at Costain, said: “This vital programme of upgrades will extend the life of critical infrastructure which keeps people and goods moving across the capital day in, day out. Our talented team, which includes Chevron and Freyssinet, set the bar for best practice delivery during the first phase of the project. Not only did the A40 remain open to the public throughout the works, but the project was completed five weeks early and under budget. This is the yardstick against which we’ll measure our success on this project.”

Mike Hardaker, TfL's Director of Capital Delivery, said: “We’re determined to ensure Londoners can move around the capital safely and easily, which is why we’re carrying out vital maintenance works on the A40 Westway. The A40 is one of the busiest roads on our network and this next phase of work will allow us to replace joints along the road, ensuring the road can continue to run safely and reliably for years to come. We’ll continue to work closely with Costain to minimise disruption to people using the road and living in the area while this vital work takes place.”

During 2023, Costain has partnered with TfL to progress a number of improvements to London’s integrated, multimodal transport network. At Gallow’s Corner flyover bridge in Romford, Costain recently undertook an optioneering exercise to explore upgrading the structure, culminating in a design which set out the most sustainable, efficient and cost-effective solution for TfL. The team is currently providing this specialist consultancy service for the planned enhancements to the Green Man and George Green tunnels.

Costain has also supported TfL with the design of important enhancements to its rail network, in readiness for a new fleet of London Underground trains. In addition to designing the upgrades to the civils infrastructure for the signalling system on the Piccadilly line in West London, Costain has created detailed designs for the refurbishment of Northfields depot, where longer platforms are required to accommodate the new trains and facilitate access for maintenance personnel.


Enquiries: Jemma Savage, Headland

[email protected]

[email protected]


Notes to Editors

About Costain

Costain helps to improve people’s lives by creating connected, sustainable infrastructure that enables people and the planet to thrive. We shape, create, and deliver pioneering solutions that transform the performance of the infrastructure ecosystem across the UK’s energy, water, transportation, and defence & nuclear markets.

We are organised around our customers, anticipating and solving their challenges and helping to improve performance. By bringing together our unique mix of construction, consulting, and digital experts we engineer and deliver sustainable, efficient, and practical solutions.