Icy road conditions are expected to continue through to tomorrow for parts of the South Island after frozen surfaces have again caused problems for road users this morning.

New Zealand Transport Agency Waka Kotahi (NZTA) has had area warnings in place again this morning with freezing conditions impacting state highways in Canterbury, the Mackenzie Basin and Otago. Several crashes have been reported across the central and lower South Island.

State Highway 1/Dunedin Southern Motorway at Burnside was briefly closed again this morning after crashes in the same trouble spot that had to be closed for a period yesterday. NZTA contractors have been out again laying grit or anti-icing agents on the highways to help keep people safe.

Latest forecasts supplied to NZTA show that hoar frosts and black ice may persist for highways in the Mackenzie Basin, south of Irishman Creek, until about midday tomorrow. Frosts are also expected to impact State Highways 1, 7, 73, 75 and 77 through Canterbury early tomorrow.

Drivers are urged to reduce their speeds, increase their following distances, and avoid sudden braking or turning movements on icy roads. Ice is more likely to form in places such as bridges and shaded areas, and black ice can be harder to spot. Staying as visible as possible, with headlights on in foggy conditions, also helps to keep people safe.