Emergency services have been called to Northwood this morning after a car crashed into a power pole.

The crash happened around 8.30am near the Groynes Drive northbound offramp on State Highway 1, forcing the closure of the offramp.

A St John spokesman said they responded with an ambulance.

One patient was assessed at the scene and transported to Christchurch Hospital in a moderate condition.

NZTA said the northbound offramp at Groynes Drive was closed following the crash, with motorists asked to use an alternative route.