A Wellington highway was partially closed this morning after a car skidded and crashed into a ditch.

Emergency services were called to State Highway 58, which crosses the Haywards Hill between the Hutt Valley and Porirua, after the crash near the SH2 intersection.

Sergeant Andy Dow of police central communications said ambulance staff were treating a woman for shock after a single vehicle skidded on the wet road and crashed about 9.20am.

The road remained partially blocked while a tow truck made its way to the scene.