A New Zealand bridge expert who has close ties to the bridge which fatally collapsed in northern Italy says it was an accident waiting to happen.

So far, 38 people have been killed after Genoa's Morandi bridge came down during a storm earlier this week.

Canterbury University Structural Engineering Professor Alessandro Palermo says he knows the person who warned that the Morandi's bridge was in excessive need for maintenance.

"The Italian professor said that the bridge needed so much maintenance after just 20 years, it would have cost just as much to replace it."

Palermo says officials do a visual check on bridges every two years including the Auckland Harbour bridge which is very closely monitored.

"At some point it will cost more for the NZTA to monitor and maintain a bridge than it will to replace it, that goes for all bridges , even the Auckland Harbour Bridge."

The engineering professor says although the Auckland Harbour Bridge hasn't been designed to last forever, regular commuters should not feel unsafe every time they drive under a bridge.

LISTEN ABOVE AS ALESSANDRO PALERMO SPEAKS WITH MIKE HOSKING