A serious crash has closed part of State Highway 76, Southern Motorway in Addington.

The New Zealand Transport Agency said the “serious incident” happened between Barrington Street and Curletts Road about 10.11pm.

Emergency services were called to the scene, and motorists were advised to expect delays or use an alternate route.

The agency said the highway was expected to remain affected until further notice.

A witness said it appeared to be a pile up of vehicles.

Another motorist said police had closed the westbound lane.