Tararua's Mayor says the Manawatu Gorge's elevation to a road of national significance is the certainty local businesses need.

It's one of ten routes National has promised to make roads of national significance if re-elected, in a $10 billion transport plan.

Mayor Tracy Collis believes it's good timing because the current closure is really starting to bite businesses.

"Going forward, it gives us a real confidence that this isn't going to happen again. They've identified the route is important and a priority. It gives a real certainty to businesses."

Ms Collis also said it's necessary as so many people utilise the route.

"It's fantastic - people were frustrated that the link hadn't been given this status and level of importance before. It's a huge lifeline link to 600,000 people."