Suffolk County Council has submitted plans for a £64m series of road improvements to the A12 have been Lowestoft and Ipswich.
The scheme will see upgrades to the key roundabouts from the A14 at Seven Hills, east of Ipswich, north to the A1152 at Woods Lane.
Elsewhere, a new dual carriageway section will replace the existing single carriageway bottleneck at Seckford Hall between the B1438 and B1079.
If given the green light, it is hoped construction work will begin in mid-2025 and be completed by mid 2027.
The Department for Transport has already allocated £54m to the project with extra developer contributions due from Brightwell Lakes development and Sizewell C nuclear power station.
Richard Smith, Conservative councillor and cabinet member for economic development, transport strategy and waste, said the improvements would “future-proof the A12 and deliver major benefits to local communities”.
He said: “The A12 is a critical bottleneck in accessing the East Suffolk coast, which is the location of several Nationally Significant Infrastructure Projects, external, including Sizewell C.
“This funding will allow us to meet the timescales of Sizewell C and minimise congestion and network disruption during its construction.”
