One person has been seriously injured in a crash involving a car and truck which has blocked Christchurch’s Southern Motorway for a time.

The crash, on State Highway 76 between the Curletts Rd on-ramp and Shands Rd off-ramp, was reported to emergency services about 3pm on Thursday.

A police spokesperson said the motorway was blocked for westbound traffic.

“The motorway is down to one lane for traffic leaving the city after a crash between a car and truck at around 3pm today.

“One person is reported to be in a serious condition.

“Motorists are advised to avoid the area at this time.”

In an update about 4.45pm police advised the road had reopened.