State Highway 8 was closed north of the Hunt Rd intersection near Evans Flat about 9.15am today and was clear by 10.30am, the New Zealand Transport Agency/Waka Kotahi advised.
Earlier, police and councils urged "extreme caution" when using roads and footpaths due to black ice, and motorists were advised to delay travel where possible.
"If you do need to travel, exercise extreme caution and patience, drive to the conditions and increase following distances," police said.
In Central Otago, the district council said areas of concern were Ranfurly, Naseby, Alexandra, Clyde, Springvale, Galloway, Earnscleugh and Bannockburn.
"Take care on corners and intersections, footpaths are also being affected.
"Slow down and drive to the conditions, increase following distances and in the fog - turn your headlights on!"
Crews would continue grit and monitor passed daybreak, as temperatures were expected to drop further.
Hawkdun Runs Road and Reef Road (Ida Valley) at Ford Crossing are closed.
Danseys Pass Road remained shut from the gates near the hotel - 4x4 access only from Ridge Road.
In the Queenstown Lakes area and Wānaka, extreme care was also advised as temperatures had dropped rapidly this morning, the district council said.
A spokesman said there was black ice on the Crown Range Road between Cardrona and the summit. Grit had been applied and trucks were out patrolling.
Black ice was forming in the Arrowtown Dalefield basin, Malaghans Roads and Arthurs Point areas.
Icy conditions were possible on the Wānaka-Cardona Road.
In Queenstown's CBD, Fernhill and Queenstown Hill grit has been applied to known high-risk areas.
Meanwhile, surface flooding was continuing to affect State Highway 85 after a snow melt.
- Allied Media
