The national transport authority is standing firm in the face of local opposition to a lower speed limit for the road between Napier and Taupō.

Waka Kotahi NZ Transport Agency insists reducing the maximum speed on State Highway 5 from 100km/h to 80km/h next month will make the road safer and it has the backing of police and road safety experts.

Local mayors have been encouraging residents to sign a petition to stop the change.

The Napier-Taupō road got a bad name when it had nine fatalities in less than a year - but there have not been any deaths in the 15 months since then.

Waka Kotahi wants it to stay that way, so it is lowering the speed limit from February 18.

Locals have lodged a petition before Parliament, asking MPs to get Waka Kotahi to reverse its decision. So far, it has more than 4000 signatures.

They argue it will be bad for the area's economy, residents, and visitors.

Napier resident Tony Alexander is one of this campaign's leaders.

"My biggest concern is that it will actually make travelling times a lot longer for some vehicles," he says.

"I believe it will increase the frustration of people who can drive faster, not necessarily need to go faster but can drive faster."

State Highway 5 between Napier and Taupō has been described as an unforgiving and dangerous road. Photo: RNZ / Tom Kitchin.

Hastings Mayor Sandra Hazlehurst shares similar views.

She and the other Hawke's Bay mayors have written to Waka Kotahi's chairman, asking him to stop the change.

"We know that the road needs to be travelled at 80 kilometres [an hour] in various hotspots and various dangerous areas, but a blanket approach isn't the answer for the community," she says.

"The nervousness around concerns of people being frustrated - we'd need slower vehicle bays, we need different engineering solutions."

Auckland University associate professor in transport engineering Doug Wilson disagrees.

"It comes down to what are we willing as a country and a society to value ... so an additional five minutes of travel time on that, compared to potentially a social cost of people being killed and seriously injured."

Wilson says according to Google Maps, the road's current average speed for vehicles is about 75km/h, so the lower limit will not make much difference for most drivers.

Waka Kotahi central North Island regional relationships director Linda Stewart says the agency did not plan to reconsider its decision.

"It's really, really important that we have safe and appropriate speeds for the types of roads that we're travelling on, but importantly that we create together a safe system that ensures that everyone that travels on that road gets home safely and in one piece to their friends and family."

Stewart and local MPs will meet those who are complaining about the new speed limit in a private meeting today.

Tukituki MP Anna Lorck is one of those who will be at the meeting.

"It's the first opportunity as local MPs that we've had to get around the table and talk to key stakeholders and that'll be an important initial first step," Lorck says.

She believes reducing the speed limit should not be the "ultimate solution".

"We need a major upgrade for State Highway 5. We need to have the confidence that we have a road map for upgrading that road because there are areas of it that are in desperate need of upgrading."

A police spokesperson says they support initiatives to ensure roads are safe, which includes the setting of appropriate speed limits.

Minister of Transport Michael Wood says a reduction in the speed limit at SH5 between Taupō and Napier will make the road safer. Photo: RNZ / Angus Dreaver.

Minister of Transport Michael Wood also supports the change.

"We know SH5 between Taupō and Napier needs to be safer, which is why Waka Kotahi will be installing infrastructure upgrades and safer speeds along the route," he says in a statement supplied to RNZ.

"This will save lives and there is nothing more important than that to me as Transport Minister. We are prepared to make hard decisions to stop the carnage if it saves lives and stops more families in Hawke's Bay from being devastated."

A spokesperson for Wood says under the Land Transport Act, Waka Kotahi is responsible for setting speed limits for state highways, and ministers and MPs were not.

Since 20 October 2020, there have been 58 crashes on the highway, with only six causing serious injury and no fatalities.

A recent speed limit drop on SH6 between Nelson and Blenheim has brought no deaths, compared to the previous two years where five people died.

-RNZ/Tom Kitchin.