Sunday, February 20 will be a big night for Welshpool which will wake up the next morning with a new road system.
Contractors working on behalf of Tesco will be putting in place the required signs, white-lining and installing traffic islands for the one-way system, which will become operational the following day.
Broad Street, Jehu Road, Brook Street, Church Bank, Mill Lane, Church Street and the new link road through Church Street car park will all become one-way for traffic.
A spokesperson for Powys County Council said: "In order to assist the public to get used to the new system, additional signing will be placed at junctions to direct motorists and operatives will be on-hand to advise drivers of the new arrangements.”