State Highway 3 in Awakino, is blocked after a truck has rolled this morning.

Emergency services were called to the incident, between Iredale Quay and Gribbin Street, about 8.50am.

Motorists are advised to delay travel due to heavy snow fall and black ice forming across Central Otago.

The Halswell Junction Road roundabout is now operating with limited lanes available, while emergency services staff continue to work at the scene.