The work is part of the project to improve connection to the Britain’s busiest airport and create a global gateway for western England.
The link will enable passengers to travel directly to Heathrow Airport from Reading and Slough without having to change at London Paddington.
As a result of this link carbon dioxide emissions should be reduced by the equivalent of 48 million passenger road-km per year. The link will provide an economic boost in the region, and ease road congestion.
The project will be executed over the next 27 months.