Four-lane extension planned to Piarere

Motorists would avoid a black spot intersection between Hamilton and Tauranga with a newly-announced roading route.

The favoured route for a four-lane extension of the Waikato Expressway - between Cambridge and the turnoff to Tauranga - was revealed on Sunday.

The four-lane highway would pick up from the Waikato Expressway and run through to ‘‘a point within 5km of the existing SH29 intersection,’’ NZTA documents say.

But more work is needed before it gets the final tick.

‘‘The Government’s announcing that we have zeroed in on the preferred route for Cambridge to Piarere,’’ Transport Minister Simon Bridges said, near the notorious turnoff.

‘‘This has been something that many have talked about and wanted for a very long period of time.’’

The project is estimated to cost somewhere between $300m and $600m.

Improved safety will be a major benefit once it’s in place, said Bridges, who is also MP for Tauranga.

‘‘This is a real black spot - one of the worst in New Zealand.

‘‘It’s for the NZTA to design [the new section] but we wouldn’t be confirming a new route and looking at this size of investment if we weren’t significantly improving the intersection.’’

NZTA said the route improvements were expected to reduce the number of deaths and serious injury crashes by more than 70 per cent. And $8.1m has already been earmarked for safety improvements in the area, such as a wide centre line, roadside barriers in high-risk areas, and a right-turn bay into Keeley’s Landing. The new road will also help the regions, Bridges said.

‘‘It connects, effectively, our capital of commerce, Auckland, with one of our hearts of agriculture, and of course the horticulture in the Bay of Plenty and the port.’’

It will cut about 1.5km of travel off the trip to Tauranga, he said, and will also shave some time off for those heading south on SH1.

The final route will be determined during the next stage of investigations.

It’s important to let people know of the early preference, NZTA regional relationships director for the Central North Island, Parekawhia McLean, said.

‘‘We are telling people that a favoured option has emerged because a project of this scope and size affects many people who live, work, do business or travel through that part of the country.’’

She added a lot of work still needed to be done, but NZTA would be keeping the public informed along the way.

NZTA said five people died and 14 were seriously injured in crashes on the route between 2011 and 2015.

‘‘The favoured option will significantly improve safety by ensuring the road has the latest design and eliminating conflict between local traffic and state highway users,’’ NZTA said in a statement.

‘‘The corridor will also improve the travel time, ensure the journey takes the same amount of time every time and improve access to places the community use.’’

The final decision will be announced later this year.