Main contractor Jackson Civil Engineering is presently in negotiations with the council to deliver the £22m A2300 improvement scheme, which could now start this spring.
Work will convert a 2.5km section of the existing road to a dual carriageway between the A23 and the proposed Northern Arc roundabout.
The scheme links Burgess Hill to the A23/M23 and is an important route for commuters, who often face congestion and delays.
The upgrades will also see the addition of new walking and cycling paths and will allow over 3,500 new houses to be built along the route, by providing a key link between the planned development at Burgess Hill and the London to Brighton corridor.
At its peak, it is estimated over 20,000 vehicles use the road daily. Without the upgrade, traffic flows are expected to grow by 40% over the next 2 decades.
The new road expected to be open in winter 2021.