Pittwater Road is closed in both directions between Warringah Road and Roger Street at Brookvalle, due to a two car crash.
Traffic in both directions can use Warringah Road, Beacon Hill Road and Roger Street instead.
Local buses are also diverting away from Pittwater Road.
Traffic is heavy through the area. Motorists should allow plenty of extra travel time.
Police and traffic crews are on scene.
For the latest traffic information, download the Live Traffic NSW app, visit www.livetraffic.com or call 132 701.
For the latest transport information, visit www.transportnsw.info