Ruthin-headquartered Jones Bros is celebrating the award of a £65.5m contract to design and construct the 9.8km Caernarfon to Bontnewydd bypass.
It is part of a joint venture selected by the Welsh Government for the contract. The other partner is Balfour Beatty.
The scheme will realign the A487 to improve journey time reliability and help economic development in the Arfon area.
Jones Bros is committed to investing locally and it has an aim that 75 per cent of the money invested on the scheme will reach local Welsh suppliers.
The Early Contractor Involvement (ECI) contract includes a requirement to assist the Welsh Government with statutory processes including public consultation.
Subject to the completion of all these statutory processes and any public inquiry, construction is expected to start in late 2016 with completion by the end of 2018.
The bypass will be single carriageway and will have alternating two lanes in one direction and a single lane in the other.
It will involve the construction of 22 structures, including seven bridges.
These include a crossing over the Welsh Highland Railway, a 300m viaduct over the Afon Seiont and a 280m viaduct over the Afon Gwyrfai and its flood plains.
Work will start this month taking the scheme through the design and planning stages. This will include public exhibitions and discussions with the project’s public liaison team, to provide accurate information relating to the scheme.
As part of the statutory process it is likely that a public inquiry will be held in the middle off 2016.
The contract also includes responsibility for the aftercare of the landscape planting for a period of five years, following main works completion.
Computer-generated 3D visualisation modeling will be used in the public consultation process. It will also be used to help deliver an efficient scheme through a diverse supply chain and for high-quality maintenance after the scheme is complete.
Huw Jones, Managing Director of Jones Bros, said: “This is fantastic news for our local workforce and North Wales suppliers. It will provide many benefits to the region’s economy.
“Jones Bros operates on infrastructure, renewables and land remediation projects across the UK, and we are delighted to have won a contract of such significance right on our doorstep.
“This will be the fourth time we’ve delivered a project in a joint venture partnership with Balfour Beatty, and the second in Wales after the Porthmadog bypass.”