Motorists travelling between Picton and Christchurch have to take an even longer route after a car crashed on the alternate route to SH1, bringing down power lines.
State Highway 63 through Wairau Valley is closed on Saturday evening after a car crashed into a power pole near Larkins Rd about 5:20pm, police say.
The two people in the car were not injured but the pole and wires have come down across the road.
SH63 is part of the alternate route between Picton and Christchurch used while SH1 is closed for repairs following the Kaikoura earthquake a year ago.
Motorists can travel south via Nelson but it will add time to their journey.