Carillion has the contract to build the new east-west road, which will link Camborne, Pool and Redruth and spur house building in the old industrial region of Cornwall.
The council received £16m in direct funding from Government and will fund the balance for the project which it claims will create more than 5,500 jobs and 7,500 homes over 20 years.
Councillor Bert Biscoe said: “Camborne and Redruth will have a much better chance to build the future they each desire when this project is achieved.
“We can then breathe new life into one of the historic industrial powerhouses of the local economy that has suffered such dramatic decline since the collapse of the mining industry.”