A Dunedin City Council spokesman said the upgrade was not yet complete, but the car park would be reopened in the interim for free all-day parking, until further notice.
The decision was made with commuters and Christmas shoppers in mind.
Access would be available only from the St Andrew St entrance.
Depending on the weather, the car park would be closed on December 17 so it could be sealed, and then reopened the following day.
"The final stages such as line marking, reinstalling pay-and-display meters and the shared path will be finished early next year."
The project involves sealing, redesigning and upgrading drainage and creating a 3m-wide shared path along the railway side of the car park.
Safer entrances and exits will be created, using gate barriers to protect pedestrians and cyclists at the St Andrew St railway crossing.
The upgrade was expected to be completed in April next year.
