Weeks of traffic disruption are expected to start in Billingshurst from Monday while roadworks take place.
Part of Billingshurst High Street will be closed to through traffic from Monday March 5 until Friday April 13 while gas mains are installed.
West Sussex County Council says that the road will be closed from High Seat Copse to the junction with Hilland roundabout. However, access will be maintained for residents, businesses and emergency vehicles.
The council says that an alternative route for traffic is via the A29, A272 West Street, the A272 High Street and vice versa.
The gas mains are being installed by the Herts-based firm of Express Pipe Laying and Repairs and will serve a new Persimmon Homes development.