The cost of the Heysham to M6 link road has increased by £1.3m as the district waits for a judge’s verdict.
Justice Turner heard the legal challenge against the decision to grant permission for the road on July 22 and 23 and is expected to hand down his decision on October 4.
Lancashire County Council said it had expected a decision within a few weeks.
Since Transport Solutions for Lancaster and Morecambe (TSLM) submitted its case on April 29, construction costs have increased by £880,000, and preparation costs by £900,000, totalling £1.78m.
However, Lancashire County Council said it had already made allowances for an extra £480,000 in its overall budget.
The total adds up to £100,000 per week extra since April. The earliest work could now start on construction of the £123.9m dual carriageway road – linking the M6 at junction 34, near Halton, to the Heysham bypass, near Scale Hall – is November.
County Coun John Fillis, cabinet member for highways and transport, said: “All we can do has been done and we, like many local people and businesses in Lancashire, are awaiting the judge’s decision.
“It can be frustrating but we feel all our efforts will be worth it in the end, this is a link to the future which will be a catalyst for success.”
But David Gate, from campaign group TSLM, said the delay was evidence that the challenge was justified.
He said: “TSLM lodged the appeal because our legal team advised that we had a good case.
“If the judge had agreed with the county council that there was no case to answer, he could have thrown it out on the day, but he has spent 50 days so far thinking about it, which shows that we had a good case and presented it well.”
Mr Gate added: “The county council have been struggling with this scheme for over eight years now and the delays are down to them.”
Steve McCreesh, project director for the Heysham to M6 Link Road, said: “The delay due to the legal challenge has increased the costs of completing the link road and we are disappointed that we have not yet received the judgement.”