The bridge first opened as a dam in 1926, with access over the top, but it was not until 1936 the road to Kingston was completed.
The final public car drove over the bridge mid-morning yesterday.
All State Highway 6 traffic is now travelling over the adjacent $22million double-lane curved bridge.
But it is not yet fully finished and traffic is restricted to one lane. Traffic lights are in place.
''Over the Christmas-New Year period, drivers were able to use one lane on each bridge with no need for traffic signals,'' NZ Transport Agency senior project manager Phil Dowsett said.
''While this worked very well, we now need to get the old bridge prepared as a walking and cycling route and complete work on the new bridge approaches.''
The northern approach to the new bridge will be completed, including underground utilities (water, power, stormwater drains), as well as the pedestrian and cycling underpass to the state highway.
The heritage bridge closure will mark a start on converting it to part of the Queenstown Trails Network for walkers and off-road cyclists.
Temporary traffic signals will be used on the new bridge until April, when it will fully open.
''Thank you to all drivers for taking care around the bridge and road building crews in the lead up to the full bridge opening, and for building in some extra travel-time until then,'' Mr Dowsett said.
