Motorists are advised to jump on public transport, with delays expected throughout the area.
AT reports detours will be put in place for 75 bus services because of the closure.
Emergency services were forced to close the street block after a cladding panel was blown off the Victoria St apartment building at about 10.45am yesterday
A witness said she heard a "very loud bang", then saw dust fly up from behind a construction fence when the panel fell just after 1pm.
Several pedestrians on the footpath below had visibly jumped at the impact before retreating to a covered tunnel.
The Auckland apartment building from which the panel fell is subject to $40 million of remedial work which began in March.
The panel that fell to the street was on the Victoria St West facade of the building.
A police officer at the scene on Thursday said an area had been roped off due to fears more panels could tumble down. Fallen debris was also blocking lanes, Auckland Transport said.
Inspector Cornell Kluessien on Thursday said traffic was being detoured as a precaution.
"The wind and the rain is the concern because now that panel is missing more water will get behind it. Between the wind and the rain another panel may get loose and blow on to the road."
The road closure caused long delays on Thursday evening.
People exiting the Sky City carpark during peak travel times experienced up to 45-minute delays just to get out on to the street.
An NZME employee said on Thursday she had spent 40 minutes sitting in her car and described the situation as "pandemonium".
