Offal causes traffic delays on St Johns Hill's Great North Road

The offal on road on St John's Hill. Photo / Bevan Conley

Whanganui traffic has been halted by an unlikely source - offal.

A 100m stop/go has been set up on the corner of Great North and Montgomery Roads on St Johns Hill to bypass the spilled waste.

System Manager of NZTA Ross I'Anson said there have been a few accidents like this over the years.

"Offal gets carted around in open top trucks and there was an accident."

The stop/go will remain until at least tomorrow night as they try to find a specialist company to clean it up as it is a "very hazardous process".

"It's not considered a biohazard until it hits the ground. Once that happens, we have to dispose and pick it up in a careful manner."

L'Anson said NZTA could not do much itself besides put sand on it and hope it dries it out so it could be disposed of.

Although offal spillage is fairly uncommon, I'Anson said NZTA was looking for a better way to deal with it in the event it happens again.