Several lanes are blocked on State Highway 2, near Lower Hutt after a motorcycle crash this morning.
Emergency services were called to the Christmas Day crash at around 9.15am, between Hebden Crescent and the Haywards Hill Road off-ramp.
The motorcyclist was taken to Wellington Hospital in a serious condition, according to a spokesperson for Wellington Free Ambulance.
Southbound traffic remains diverted over the Haywards interchange, police said just before 11am.
As a result of the crash, State Highway 2 was earlier closed in both directions, but has since re-opened for northbound traffic.