The project involves the construction of a new off-line bypass to the east of the town of Dalry in Ayrshire and associated junctions to connect to the existing A737 trunk road.
The contract notice published last year had the construction costs in the range of £34m to £38m. Farrans Roadbridge Joint Venture has agreed a price of £31.2m.
Works include the construction of a 4km bypass, with roundabouts at Hillend and Highfield, and a viaduct over the River Garnock and the Glasgow to Ayr railway line. Works are also required to connect the new bypass to the existing A737 trunk road east of Highfield.
Scotland’s transport minister, Humza Yousaf, said: “Over the past few months, preparatory works have been undertaken on the site including archaeological investigations, fencing and vegetation clearance. The award of this contract, subject to the mandatory standstill period, enables the main works contractor to finalise its designs and establish a base on site before it can begin the main construction works in the coming weeks.”
Also on the shortlist for the contract was: Balfour Beatty Civil Engineering; Interserve Construction; and John Paul Construction in joint venture with Portuguese contractor Somague Engenharia.