SH1 Tīrau to Waiouru maintenance update

25 August 2025

Current and upcoming works

East Taupō Arterial: Night work continues. Stop/go traffic management, between 7pm and 6am, Sunday to Thursday. Expect some delays.

Taupō to Tūrangi: Road rebuilding. Starting at Waitahanui on Monday 1 September. Stop/go traffic management during the day for around 2 weeks, then temporary speed limits. Expect some delays.

Tīrau: Nighttime only road closure. Starting Sunday 14 September. Work between the hours of 7pm and 6am Sunday to Thursday (no weekend work). Detour is via State Highway 27 (SH27), Patetere Street, Okoroire Road, Hetherington Road, State Highway 5 (SH5) and back to State Highway 1 (SH1). This adds approx 6 mins and 10km to your journey.

All of this work is weather dependent.

Turning up the heat for T2W in season 2

T2W has a new team member for season 2 as we turn up the heat on our road building.

With a knack for keeping things hot and a wanderlust for fresh roads, Cindy, the Mobile Asphalt Plant (MAP), has been employed on T2W to deliver the asphalt needed on our sections of work between Taupō and Tūrangi and on SH1 Desert Road. 

Cindy, named by contractor Downer, is already well known across New Zealand and the Pacific where she’s been helping keep communities in Tuvalu, Queenstown, Te Anau, Transmission Gully and Gisborne, to name a few, connected, one stretch of asphalt at a time.

Cindy has rolled into the T2W project to help us deliver up to 160 tonnes of asphalt per hour to where it needs to go within a 2-hour window of it being produced.

From her location between Taupō and Tūrangi, the T2W team will be able to deliver asphalt to most of our sites between Taupō and Tūrangi and on the Desert Road within 1 hour and many of them within 15 to 20 minutes. 

For each type of road surface we need to deliver, Cindy is preprogrammed with a specific recipe. The recipes are all determined based on our specifications (specs) and take into consideration the ground conditions under the road, what type of base we’re building the road on, and the type of surface we need to deal with the traffic.

Once the recipe is chosen, Cindy gets to work mixing the ingredients together, heating it to around 180 degrees. When making asphalt, timing is everything, which is why it’s so critical to have Cindy close to where she’s needed.

Once it’s ready, the hot asphalt is loaded into our trucks and taken directly to where it’s needed. The asphalt temperature is measured before it leaves Cindy and again before it’s applied to the road surface to ensure it’s at the ideal temperature.

Once the truck arrives at the road site, the mixture is loaded into a paver (a type of machine that specialises in laying asphalt) and then the crew meticulously gets to work.

To give you an idea of the volume of asphalt being used on T2W this season, the work on T2W equates to around 20 percent of the whole asphalt volume for Downer across New Zealand this season.

The amount of one particular specialised binder being used on T2W over a 3-month period, a critical ingredient in making asphalt, is equivalent to the total amount of that binder our contractor Downer would use in a usual road maintenance season across the entire North Island. They have planned for this, bringing in more product to get the job done. We’re completing the final surface on 5 areas of SH1 where we worked last season. Asphalt for the other sections is coming from the fixed asphalt plants in Hamilton and Rotorua.

Work sites between Taupō and Tūrangi have been sequenced to minimise delays as much as we can during our work between September and mid-December, but please plan for some delays when you’re traveling through this area. We know roadworks are an inconvenience, but the work does need to be done.

Tīrau - nighttime closure and detour

Work will start at Tīrau on Sunday 14 September. We are using a nighttime closure to complete this work because of the narrow road width.  Work will start at 7pm and stop at 6am every night between Sunday and Thursday for one month.

The detour during this time will be via SH27, Patetere Street, Okoroire Road, Hetherington Road, SH5 and back to SH1.

During this time we will be rebuilding the road between Tīrau and the roundabout, replacing the kerb and channel and repairing culverts and drainage.

We will then switch the traffic management configuration to complete work on the roundabout at SH1/SH5 in early October and will share our traffic management plans for that shortly.

Other work near Tīrau that’s not part of T2W

There are other road maintenance projects happening in the area that are not part of T2W. These include:

• The construction of a roundabout at SH5/SH28-Harwoods Road.
• Widening SH5 between Whites Road and Waimakariri Road
• A rebuild of 400m of SH28-Whites Road from the SH5 intersection, including a new asphalt final surface at the intersection.

As we mentioned in our last newsletter, this is always the busiest time of year for roadworks.  Check out our Journey Planner before you travel. You can also sign up to our other road maintenance newsletters to keep up to date with works in your area.

Harwoods Road intersection.

East Taupō Arterial – milling off the bumpy parts

T2W started work on the East Taupō Arterial (ETA) last Sunday night. We’re doing Asphalt Concrete (AC) in areas where we didn’t work last season.

To simplify the roading engineers’ feast of acronyms - we’re taking the bad bumpy parts off the top of the road and replacing them with something stronger. AC is a durable road surface that can carry the weight of a high number of vehicles traveling across it every day.

Once we complete this work, we will be coming back in February 2026 to put the final smooth surface on the road so you will see us out on the ETA a few times this road maintenance season.

Night works on the ETA. Milling to remove the existing pavement and checking the depth before placing 1 of 2 layers of structural asphalt.

Wide load follows

Size really does matter on our roadwork sites. We go to great lengths to make sure all road users can plan their journeys and get to where they need to go with as little disruption as possible or at least plan for the disruption and factor it into their trips.

One group we work closely with are operators hauling over dimension loads. In season 1, T2W got more than 70 oversize loads through our sites, including many houses. We had our first oversized load on the East Taupō Arterial last week.

More information

For more information on the SH1 Tīrau to Waiouru maintenance, contact us at SH1Waikato@nzta.govt.nz

Visit our website nzta.govt.nz/t2w