Consultants Ramboll and Parsons Brinckerhoff have now been confirmed to start design work on TfL's Structures and Tunnels Investment Portfolio.
The two consultancy firms will develop designs for reconstruction and refurbishment work on a number of TfL structures and tunnels during the next few years.
The portfolio, which will cost around £200 million to deliver, has been split into three work packages and will mean improvements to the following structures:
- Work Package 1 consists of the Upper Holloway Railway Bridge and Highbury Corner Bridge on the A1, the A127 Ardleigh Green Railway Bridge and the A406 Power Road Railway Bridge
- Work Package 2 consists of the A406 Fore Street Tunnel, Chiswick Bridge on the A316 and the reconstruction of the woodlands retaining wall on the A406 near Golders Green
- Work Package 3 consists of the second phase of improvement works on the Hammersmith Flyover, following the successful restrengthening works during Spring 2012
Tfl said contractors "will be key to the success of the design process" under the Early Contractor Involvement (ECI) Framework.
Hochtief and Volker Fitpatrick are believed to be among those chasing a place.
Dana Skelley, Director of Roads said: "Early contractor involvement enables us to achieve best value for money by getting the wisdom of construction experts at the beginning of project development, helping to remove risks which are sometimes not considered early enough in traditional delivery models.
"By using this method, we can ensure we complete these important works efficiently and successfully, with minimum disruption to London's road users."
Project Director for Ramboll Parsons Brinckerhoff Ian Bolton said: "We are proud that our tenacity, creativity and strong emphasis on collaboration have enabled us to win out over stiff competition, and we can bring to TfL the tremendous technical and professional synergies our two companies are able to offer."