Graham has been appointed to carry out initial works on the Hereford Western Bypass after signing a preconstruction services agreement (PCSA) with Herefordshire Council.
Data provider Glenigan values phase one of the scheme at £45.3m.
The contractor said it secured the PCSA role through the Pagabo Civils and Infrastructure Framework.
It will lead design and technical development for the first phase of the project.
Phase one will deliver a 3.6km single carriageway linking the A49 Ross Road–Rotherwas Access Road roundabout with the A465 Abergavenny Road, with onward connection to the B4349 Clehonger Road.
The route will include several structures and underpasses, including a bridge spanning the Hereford–Newport railway line, which connects the Midlands with South Wales.
Engineering consultancy AtkinsRéalis has been appointed by Graham as multidisciplinary design partner, providing highways, civil, structural and environmental services.
The bypass is intended to reduce congestion on roads in south Hereford by diverting traffic from urban routes and improving access to the Hereford Enterprise Zone.
Andrew Henry, contracts director at Graham, said: “A project of this size and scale can prove complex, so it is great to be involved early in the process to mitigate risks and plan for success.”
Environmental measures included in the design comprise wildlife crossings, sustainable drainage, habitat creation, hedgerow planting and wider landscape mitigation.
Construction is expected to start in December, with phase one scheduled for completion by the end of 2028.
A main construction contract will be awarded in the summer, Graham said.
Source: Graham announcement