Traffic is backed up on Auckland’s Southern Motorway (SH1) this afternoon after a vehicle reportedly rolled on its roof.

Two southbound lanes between Ellerslie Panmure Hwy and Mt Wellington Hwy have been blocked as a result of the crash.

A police spokesperson said three vehicles were involved in a crash about 3.30pm.

Traffic has backed up to Spaghetti Junction following a three-vehicle crash on Auckland's SH1 near Penrose. Photo / Google

“One person has suffered a minor injury.”

Police said all but one southbound lane had closed and encouraged motorists to delay their journey home or find an alternate route.

Shortly after 4pm, traffic had backed up to Spaghetti Junction, almost 10km away from the site of the crash.

NZ Transport Agency (NZTA) advised commuters to expect delays and “pass with extra care”.

At 4pm, NZTA estimated it would take commuters two hours to drive from Auckland City to Bombay via SH1, almost fours times longer than if traffic was free-flowing.