Mt Messenger Bypass

The Mt Messenger section of the state highway network is strategically important to the Taranaki region and provides access to northern markets and export outlets, tourism linkages and access to health, cultural and other services.

Client

  • Waka Kotahi NZ

Project Value

  • $200 million

Project Partners

  • The Mt Messenger Alliance brings together Waka Kotahi NZ Transport Agency, Downer, HEB Construction, Tonkin & Taylor, WSP, Holmes Consulting and Isthmus.

Improving the safety of travel on SH3, enhancing resilience and journey time reliability

The Mt Messenger section of the state highway network is strategically important to the Taranaki region and provides access to northern markets and export outlets, tourism linkages and access to health, cultural and other services.

However the current route is narrow and steep, and increasingly unable to reliably support the 2,500 vehicles – including large trucks – that use it daily.

Following in-depth community and stakeholder consultation over proposed routes the current route was announced in August 2017.

The Mt Messenger Bypass involves the construction and operation of a new section of SH3, bypassing the existing steep, narrow and winding section of SH3 at Mt Messenger which is prone to natural hazards that can affect road safety and result in traffic restrictions, delays and/or road closures for the road users and surrounding communities.

The bypass is 5.2km long with additional work at the southern end creating about 6 km of improvements, including a bridge about 110m long and an estimated 230m long tunnel under the ridgeline south-east of Mt Messenger.

Improving the safety of travel on SH3, enhancing resilience and journey time reliability are key project outcomes, along with a strong focus on managing environmental effects.

Long-term involvement                    

WSP’s involvement with the route dates back to our days as the Public Works Department. The current road through the Awakino Gorge was first surveyed in 1914 and the Public Works Department began construction of the road in 1922.  It is believed the Awakino Tunnel, which is cut through a 25 million-year-old Oligocene limestone ridge, was formed at the same time. Reports from the time describe the process as a great task that required blasting and removal of thousands of tons of papa and limestone to create a road of reasonable width and grade.

Of all the large infrastructure projects I’ve been fortunate enough to work on, the outstanding attention to environmental and cultural outcomes has been a career highlight. This is credit to the shared vision of the Alliance team and all the people that made this happen
Tony Coulman Project Director

Key Facts:

  • The highway between Awakino and Mt Messenger is a high-risk stretch of road where 11 people have died and 45 have been seriously injured in crashes between 2007 and 2017.
  • The new road will reduce grades, have a shorter length and height climbed which will result in lower vehicle operating costs
  • It will significantly improve the connectivity of freight to and from the Taranaki Region
Percent of vehicles using the corridor are heavy vehicles
20 20
Vehicles per day on the existing corridor
2,300 2,300
The year originally built
1896 1896

Digital Engineering Capability

The new $200 million bypass with a bridge and a tunnel will provide a faster route with a lower and less steep gradient through the Mt Messenger section of State Highway 3 north of New Plymouth.

It passes through steep and inaccessible terrain that has presented considerable design and construction challenges.

Glenn Coppard, WSP Technical Principal -Transport Design, coordinates the Digital Engineering aspects of the project and says the virtual insights achieved through technology have been invaluable.

He says the use of virtual 3D Computer Models and physical 3D Printed Models have been of huge benefit to ensure all parties involved in the process have a similar understanding of the constraints and extents of the proposed works.

“Technology has played a key role in ensuring everyone has the same view of the project, it provides a level playing field. On Mt Messenger, digital engineering tools have allowed us to manage the earthworks footprint in a way that wouldn’t have been possible in the past. It also bridges the gap between paper and reality.”

For example, Glenn says that when cut backs were viewed on paper it was obvious that they were steep, but it wasn’t until they were viewed in 3D that the team realised how deep they went. That insight provided value to the design of the construction, saving time and mitigating risk.


Environment Expertise

A key focus of the Mt Messenger project is to reduce the risk of harm to native wildlife during and after construction of the road. As a result, the project includes a substantial environmental programme that includes intensive, multi-species pest management over an area of 3,650 ha and restoration planting.

Within this work a team of 25 ecologists from the Mt Messenger Alliance broke new ground in gathering information about the habitat of long-tailed bats, a critically endangered species, during field work in 2018/2019 breeding season.

WSP ecologists Doug Bridge, Caitlin Dodunski, Mark Yungnickel and Lance Robison were part of the 25-strong team who worked all hours to trap and track bats using a range of techniques including thermal imaging cameras.

Doug Bridge says working in the Mt Messenger forest has presented some unique challenges - as well as unexpected delights.

“We camped out, which isn’t typical for most of our projects. I’ had my first go at sleeping in a hammock which was interesting. I wouldn’t call it motion sickness, but it felt like trying to get to sleep on a boat. On site we eat freeze dried food and work extended hours round the clock” he says.

Although it’s been hard work, Doug says the team was keen to go the extra mile for the project and they’ve all felt immense satisfaction.

“Pest management is a major component of the Mt Messenger project and it’s vital for the ongoing survival and reproduction of the forest itself and the organisms that live in it.”

Finding bat maternity roosts will help determine the parameters of where that pest management is targeted.

WATCH: See more on this exciting investigation here.

 

Working in Partnership

The Mt Messenger Alliance is made up of transport designers, engineers with geometric, geotechnical, structural and construction expertise, RMA planners and environmental specialists including ecologists, landscape architects and stakeholder and communication professionals.

Tony Coulman, Project Director, says from day one Alliance members came together around a shared vision and commitment to collaboration.

Throughout the project the Alliance has worked closely with Ngāti Tama to build a trusting relationship that ensures manawhenua is respected and kaitiakitanga upheld.

This approach ensured that Ngāti Tama, in the traditional role as northern “gatekeepers” of the wider Taranaki region, has input to the different aspects of the bypass project including the design of the bypass route, the project’s cultural expression and its large environmental programme.


Key Project People

Doug Bridge - WSP Ecologist

 Doug has the WSP team of ecologist working alongside a wider Alliance team to carry out intensive investigatory work on the Mt Messenger project.

While some of the work has been hard Doug says the team was keen to go the extra mile for the project and they’ve all felt immense satisfaction.

“Pest management is a major component of the Mt Messenger project and it’s vital for the ongoing survival and reproduction of the forest itself and the organisms that live in it.”

Glenn Coppard - Design Manager

Glenn has over 20 years of professional experience with extensive skills in civil engineering design, drafting and documentation. He’s been involved in the Mt. Messenger Bypass for the last two years working alongside planning and construction teams to develop a range of options for the Multi Criteria Analysis, and the preferred route for consenting of the proposed scheme.

His commitment to consistently designing innovative engineering solutions tailored to the site has been of huge value on the project.

“Using technology is one of the most powerful tools we have and it has been really valuable on Mt Messenger. We’ve been able to use it for public engagement to create a digital representation of what it will look like. For stakeholders to be able to see what the project will look like and what effect it will have, that’s really powerful.”

Glenn carried out detailed development of the projects temporary works and construction sequencing, which has been key to understanding the effects of the project, not only on the environment, but the cost and programme implications. 

Tony Coulman - Project Manager

Tony’s extensive experience in leading consenting and design teams on major highway and infrastructure projects has been invaluable in his role as Project Director on the Mount Messenger Project.

“I’ve thoroughly enjoyed working on this project which has offered up challenges and opportunities. Stand outs for me include the incredible focus on environmental outcomes and the innovative use of digital tools within an alliance to ensure we are delivering to a shared vision.”