A line of congestion 10km long north of Auckland and delays of up to 90 minutes elsewhere have hit NZ highways as traffic continues to build.

An elderly driver who caused a "horrendous" multiple-vehicle smash on Auckland's Southern Motorway has received a six-month driving ban and a $1000 reparation order.

Drivers should prepare to unlearn NZ's unique intersection rule which sees left-indicating vehicles yield to opposing traffic turning right.

Auckland checkpoint backs up to Hampton Downs. Video / Auckland Checkpoint Watch