Bosses overseeing the new Corby relief road say the £34m scheme is on budget and should be finished on time next spring.
But Tony Ball, the project manager, said he was unwilling to put a date on the completion, warning a winter of adverse weather could cause delays in the dual carriageway’s opening.
He said: “I am happy with the budget and I am reasonably happy with the programme.
“We are still looking to open in early May. I am not going to promise that yet, but we are hopeful.
“We still have a winter to go.”
Some motorists have complained the work to build the four-mile stretch of road – about half of which is so far tarmaced – has caused unnecessary disruption, particularly at the Stanion roundabout.
But council chiefs say the project would be worth it, describing it as an anomaly that Corby was not directly connected to a dual carriageway.
Council leader Jim Harker said: “The Corby link road is a really important piece of transport infrastructure in the north of Northamptonshire.
“It provides Corby with its first dual carriageway link from an important town right down to the A14 and then heads to the M6 and the M1.”