The proposed Western Rail Access to Heathrow includes a new direct, double track link between the Great Western main line at Langley in Berkshire (16 miles west of Paddington Station in London) into Terminal 5 at Heathrow airport. The link is expected to provide greater connectivity from south Wales, the west of England and the Thames Valley; making journeys faster, reducing congestion on other routes, and providing significant economic benefits for businesses in the region. The project also aims to reduce CO2 emissions by the equivalent of a million road passenger trips to and from Heathrow.

Jacobs Group Vice President Bob Duff stated, "Jacobs is delighted to continue to leverage our global rail experience on this planned project. We look forward to contributing tangible solutions to support Network Rail’s emphasis on sustainable design at the heart of the new rail link."

Jacobs delivered pre-feasibility and feasibility studies in the early planning stage of the project which identified significant potential cost savings. Currently in public consultation, if the Western Rail Access plans are approved, it is expected that the new service would be in operation by 2021.