DELAYS to the completion of a £22 million relief road have been blamed on designers having to work "in the dark" due to lack of access to the site.
A designer working on Taunton's Northern Inner Distributor Road (NIDR) said he was unable to get on site at all as he drew up plans for the mile-long carriageway.
Somerset County Council denies the claim concerning the congestion-busting road from Staplegrove Road to Priory Avenue, which is already two years late.
The designer, who wishes to remain anonymous, said: "I was not allowed access to the site between Staplegrove Road and the bridge over Station Road because at the time the land was owned by Network Rail.
"They demanded a payment from the council, which didn't want to pay for visits to the site, which were probably about £1,000.
"And the council wouldn't buy the land until it had reassurances they'd get funding from the Government to pay for the road.
"The team that designed the bridge probably only went up there once. I didn't get access once - that section of road was designed blind, completely in the dark."
He said he found out about a number of retaining walls along the route "by chance", but was unable to inspect them to see how thick or how deep they were.
"Further investigations were needed," added the designer. "If you can't get access to the site, then you're guessing.
"What's happened to cause the delays could have been predicted.
"Carillion as the main contractor is getting a hard deal, but it's not all their fault.
A County Hall spokesman said: "We don’t recognise those figures and cost was not a factor. Teams were able to access the site when required."
He added that the council is in dispute with Carillion and will "pursue damages from the contractor for every day of delay".
He said he is unable to give a completion date as the authority's engineers will need to get on site to check it is safe to open once Carillion has finished its work.