Work starts at Southwick Station on Monday to relay Station Road and refurbish the drop-off and pick-up areas.
The work is part of a £5 million scheme to try to improve the route between Shoreham and Brighton and Hove along both the A259 seafront road and the railway line.
Disruption is expected in the area for 11 weeks – until the end of January.
Station Road is being realigned to line up more closely with the railway bridge.
West Sussex County Council is resurfacing the whole of Station Road as part of the scheme and aims to improve the area’s drainage.
Cyclists and pedestrians have been promised better access to the station, including a better link to and from the South Coast Cycle Route.
Lionel Barnard, deputy leader of West Sussex County Council, said that the train operator Southern would also put in CCTV, new cycle racks and waiting shelters on platforms.
The Homes and Communities Agency – a government quango – put up the £5 million in support of the Shoreham Harbour Regeneration Project.