A potential upgrade to the main Manawatu Gorge detour route is likely to be at the expense of other regional projects.
The Transport Agency wants to upgrade the Saddle Road at a cost of $4.5 million in the next three years, to ensure there's a safe and suitable alternative route when State Highway Three through the gorge is closed.
The route has now been closed for more than 200 days because of a slip and the Saddle Road, which is narrow and not designed for heavy traffic volumes, has stuggled to cope with 4000 vehicles per day.
The agency, which has been working with Tararua District Council, made sure an upgrade proposal was in the latest regional land transport programme.
Documents obtained under the Official Information Act show that given the regional funding situation, securing funding will likely come at the expense of another current regional priority.
The agency says the region's mayors, Jono Naylor, Ian McKelvie, Roly Ellis and regional council chair Bruce Gordon, are aware this will result in a project trade off, which would need to be debated by the Regional Land Transport Committee.
In a letter to those same mayors, former Transport Minister Steven Joyce said regional funds would have to be used before national funds.
Bruce Gordon says it's likely a second crossing over the Manawatu River for Palmerston North would need to be deferred because of the Saddle project.
The Vision Manawatu agency estimates the closure of the gorge is costing the regional economy $62,000 per day.
That means the current closure has cost more than $12 million.
Some $11.5 million has been set aside by the Transport Agency to clear the gorge slip and maintain the two detour routes.
Palmerston North MP Iain Lees-Galloway says the proposed upgrade should not come at the expense of other regional projects and it should not lead to other projects being deferred.
"It's typical of the National Party to require local government here in the regions to fund what is really a road that should be of national significance," he says.
Viaduct or tunnel to replace gorge extremely unlikely
Documents show the Transport Agency has all but discounted building a viaduct or tunnel to replace the Manawatu Gorge route.
In a briefing document to its minister in October, the Transport Agency said it's unlikely a new alternative route, such as a viaduct or tunnel, would receive funding given its high costs and the current direction of the Government Policy Statement on land transport funding.
While a full investigation into such alternatives is yet to be completed, the agency says a viaduct is estimated to cost more than $750 million.