The 3.9km bypass project was approved by the government last year and is expected to cost £47m to build.
Following initial preparation works, which will be taking place over the coming months, the target date for the main construction work to start on the bypass is Spring 2024.
Cllr Graham Plant, Cabinet Member for Highways, Infrastructure and Transport, said: “The new road will not only solve the transport issues caused by the bottleneck on the A140 – which is a major local route – but also open-up improvements for cycling and walking in and around the town. Once in place the scheme will cut congestion, unlock economic growth, and improve journey times across the county.”
Gavin Pritchard, managing director Highways, Octavius Infrastructure, said: “We are delighted to be working with Norfolk County Council on such a key project.
“Our carbon reduction measures, the protection and enhancement of the local environment, and the significant sourcing of local suppliers in this region reflects our strong commitment to our sustainability and social value goals for this project.”