Construction of the first two sections of the Lyminster Bypass is set to begin in next year.
Plans for the multi-million pound road were given the go ahead by West Sussex County Council earlier this year.
Work will start in January, with completion due in February 2021, providing part of a new strategic north-south road to reduce traffic and improve access in and around Littlehampton.
These two sections of road, being delivered by Persimmon Homes, will run from the Fitzalan Road, by Littlehampton Academy, through to a new roundabout in Persimmon Homes Hampton Park development in Littlehampton, including a bridge over Toddington Lane and the railway line.
A spokesperson from Persimmon Homes said: “This is an exciting development for Littlehampton, which will bring enormous benefits to local people. By reducing traffic and congestion in and around Littlehampton, travel times will be improved, and many roads will become quieter as there are fewer cars on the roads.
“A new bridge over the railway line will also reduce travel times and improve safety as drivers will no longer have to use the level crossing.
“There will also be significant economic benefits to the development. By improving access in and out of Littlehampton, more people will be encouraged to visit the town, boosting commercial opportunities. “Furthermore, as part of wider plans for Littlehampton, a new commercial centre at Hampton Park will become accessible, enhancing employment opportunities in the area.
“During construction we will aim to minimise disruption on the roads. Most of the work will not be on existing roads, so will cause minimal disruption, but the new roundabouts and connections will require short term disruption to ensure the safety of the workforce. There will be temporary speed limits and other traffic management measures put in place, which we will inform road users of with plenty of notice.”