Work has started on the main deck of the new £1.9bn Mersey Gateway bridge.
Teams will also begin to connect the steel support cables to the deck and upper pylons this summer.
The first of the two approach viaducts to the six lane bridge has been cast to the north, with work on the south approach viaduct starting imminently.
The £1.86bn cost includes maintenance and operations until 2044.
The Merseylink Construction Joint Venture, led by Kier, said it has contributed £129M to the local economy through the appointment of 351 local suppliers and subcontractors, including Manchester-based construction firm PP O’Connor and Chester-based drainage specialist Lanes Group.
Merseylink general manager Hugh O’Connor said: “Two years ago we set out to build an iconic structure, an amazing new bridge which will help to transform and improve the road network across Halton. We’re well on the way to doing that and opening on time in autumn 2017.
“As a global consortium we have brought expertise from across the world to deliver this project and it has always been important to us to maximise the regional benefits, which is why I’m very pleased that we’ve been able to place work valued at £129M within the north west economy.”