The bypass route for the Mt Messenger section of State Highway 3 (SH3) announced at the end of August is a prime focus of improvements for the treacherous 58km stretch from Awakino Gorge to Mt Messenger.
The 6km bypass route (Option C in the June 2017 public engagement) runs east of the existing highway and includes a bridge about 120m in length over an important wetland, and a tunnel about 230m long under the ridgeline southeast of Mt Messenger. The route is almost 1km shorter than the existing route.
The bypass is part of a suite of SH3 improvements that also include a two- bridge bypass of the Awakino Tunnel and general safety improvements.
“The bypass is the optimal solution for the Mt Messenger section of highway,” says NZ Transport Agency director regional relationships Central North Island, Parekawhia McLean. “It will help connect and develop the region while improving safety, resilience, and route availability that meets the public and the Transport Agency’s desired outcomes. It’s also the most cost- effective solution at around $200 million.”
McLean says the route selection takes into account the important environmental and cultural considerations in very challenging terrain. Five potential routes were investigated and assessed and this route was selected following a robust process involving key stakeholders, the community and technical specialists.
“The new bypass will be more resilient than the existing route and the other proposed bypass options because it avoids large areas of unstable land, which currently contribute to lengthy road closures and delays for customers. It is also lower providing a less steep, faster route with significant benefits for heavy vehicles.”
McLean says the bypass passes through areas with relatively lower ecological values than the proposed route options located west of SH3, and the bridge significantly reduces and controls the route’s impact on the wetland’s ecological values.
Construction on the new bypass is expected to start in late 2018 and be completed in 2021.
Safety improvements under way on high-risk highway
Work to make the section of State Highway 3 between Awakino and Mt Messenger safer is progressing well. The work includes adding roadside safety barriers, removing trees and bushes to make it easier to see the road ahead, new signs and creating a pull over area for drivers to rest or let other vehicles pass.
Electronic warning signs will be introduced to four high-risk locations. The road south of Mokau is particularly risky for motorcyclists so barriers here are being fitted with a special rail at road level that helps protect motorcyclists if they crash.
The expected completion date for the current works is April 2018. They pave the way for more extensive work next year, which will include adding passing lanes at the western end of Awakino Gorge and north of Tongaporutu to make it safer for vehicles to pass and reduce driver frustration. Slow vehicle bays will also be created within the Awakino Gorge to allow vehicles to safely pass trucks and other slow-moving vehicles.
Work continues ahead of construction
Work also continues ahead of a 2018 construction start of the Awakino Tunnel Bypass. Earlier this year a bypass involving two bridges over the nearby Awakino River was the preferred option to improve safety and efficiency at the Awakino Tunnel.
The design and construct tender process is under way and full construction is likely from October 2018 to May 2020. The bypass will take traffic away from the one-lane tunnel and existing narrow section of riverside road, which has been problematic with rock falls and slips.