During September, Norfolk County Council will be asked to approve the business case for the West Winch Housing Access Road so it can be submitted to the Department for Transport.
It is part of the infrastructure planned for 4000 homes which are planned to be built in the West Winch area over the next 20 years.
The report, to be considered on September 4, says the cost has risen from £64m to £84m mainly due to inflation.
If the money for it is found, construction would start in 2025 and it would be complete in two years, according to the document.
Graham Plant, the county councillor responsible for highways, infrastructure and transport said: “The West Winch Housing Access Road is an important project for King’s Lynn and West Norfolk. It not only supports the planned housing and economic growth in the area, but it also provides a solution to long-standing traffic issues on the A10.”
“We are working closely with the borough council to bring this project forward as soon as possible. We know that residents want to see the road approved and built in good time and we are working hard to deliver it.”