SH1 Tīrau to Waiouru accelerated maintenance project update

SH1 East Taupō Arterial opens 2 days ahead of schedule

6 December 2024

What’s happening on SH1 between Tīrau and Taupō

The northern section of State Highway 1 (SH1) East Taupō Arterial is now open. Temporary traffic management is in place so please drive carefully on the new road surface. 

Check out the great video of the sealing work that went on south of Tokoroa while SH1 was closed. 

Here’s a quick summary of what’s happening on the rest of SH1 and what’s coming up.

Current closure:

• SH1 between Putāruru and Tokoroa until Friday 20 December.

Upcoming closures:

• SH1 between Tūrangi and Waiouru (includes Desert Road) will close from Monday 13 January for approximately 2 months
• SH1 from just south of Tīrau to just north of Putāruru, planned night closure, rescheduled to early next year. Testing on the surface continues next week.

Open but under temporary traffic management:

• The northern section of SH1 between Upper Ātiamuri and Wairakei. 

We recommend checking the NZTA journey planner for more information on closures and travel times.

SH1 Eastern Taupō Arterial will be swept and line markings put on today and should be fully open without traffic management later today.

East Taupō Arterial now open

The northern section of the East Taupō Arterial (ETA) re-opened to traffic on Wednesday, 2 days ahead of schedule. 

The road opened under temporary traffic management for traffication (for more about that see the story below). Considerate driving is needed while the road is bedding in.

The line markings will go in today, the road is being swept, and  traffic management will soon be taken away including the removal of the temporary speeds. 

We’d like to thank motorists and the Taupō community for their patience while we carried out this work.

More about traffication

Another word from the road builders dictionary that you may have heard is traffication. Here’s what traffication means and it explains why road cones may guide you to drive over different parts of the road.

After sealing a new road, the surface is covered with loose stones (aggregates or chip) that need to stick and bond onto the newly constructed road beneath.

This is initially achieved with pneumatic tyred rollers (see photo below) but as the road needs to be opened as soon as possible because of the detours and inconvenience to people travelling, the initial bonding and embedment period is not fully complete. 

To finish this process when the road opens, we use traffication. This is where traffic patterns are carefully controlled using cones and specialist equipment for the first few days to help with this bedding-in process. 

The road crews place cones in strategic patterns, encouraging vehicles to spread evenly across the road’s width. The cones are moved regularly to ensure every section of the road receives an even amount of traffic, helping the chip embed evenly into the surface. 

If the traffic were left to follow a single line of travel (called channelising) then that lane may embed too far, leading to an uneven surface.

Temporary speed limits are used to prevent vehicles from driving too fast, which can dislodge loose chip. 

Traffication is usually required for at least 48 hours after sealing . 

By carefully managing traffic during this critical period, the road surface bonds properly and the chip embeds firmly.

This process prevents issues like loose chip stripping in wheel tracks, or flushing, and ensures a smooth durable pavement that will perform to its intended lifespan. 

Stabilising SH1 between Putāruru and Tokoroa

This week crews have been busy with stabilisation work on the rebuilt sections of road and this should be finished today. 

There will be small amounts of sealing done this weekend, with the main sealing drive happening next week. 

Testing and surveying will be happening over the weekend too, with some work on the guardrails scheduled. 

The large parts of the highway where we have just finished the stabilisation will see little work happening on these sections but don’t worry, there is important work going on – curing. This is a vital part of the process of road building.  

The stabilised surface has to cure correctly before the sealing works take place. On Friday afternoon when the stabilisation has finished, the work in the laboratory starts and this takes about 4 days to complete. 

The independent WSP lab in Rotorua conducts tests on the material.  Primarily they are looking to check the strength of the road, to ensure that the right amount of binders (cement and bitumen) have been added.  Key tests are the density and checking moisture levels.  

This is done at the same time the newly stabilised road is curing. Having vehicles on the newly stablilised surface can result in a poor quality finish. There is a big focus on quality in this project.

Just like pouring concrete, you need the road to cure or you’ll end up with an uneven surface.  

With the effort we’ve gone to close sections of SH1, and the inconvenience that causes for businesses, local communities and motorists, we want to make sure we do the best job possible.

If you can't see lots of people in their high viz out working this weekend on the road, don't worry, the work is happening in the labs and within the road itself. 

Please take care on the Putāruru to Tokoroa detour

A reminder to please take care on our detour routes. Many of them are narrow and winding especially when compared to SH1. A temporary speed limit of 70 km/h is in place on this detour route to help keep everyone safe on these local roads.

The detour from is (from north to south) Princes Street, Arapuni Street, Arapuni Road, Old Taupō Road, SH32 - Tokoroa and vice versa. This adds approximately 20 mins and 18km to journey times compared to the normal trip from Putāruru to Tokoroa down SH1. 

New warning signs have been installed to help remind motorists that the route is seeing more traffic than would usually be expected on a country road.

The detour for HPMVs travelling from Tīrau to Taupō is State Highway 5 and trucks should use this rather than local detours. 

Ironman athletes arriving in Taupō

Some of the world’s best endurance athletes have begun arriving in Taupō to swim, bike and run the Ironman 70.3 World Championships for 2024.

Regular users of SH5 and Broadlands Road should expect to see cyclists on the road in the comings days as the athletes familiarise themselves with the cycle leg of the event of 14 and 15 December. 

The cycle leg uses SH5 between Wairakei and Golden Springs, which will be closed from 6am to 5pm on Saturday 14 December and again on Sunday 15 December. 

Traffic travelling between Taupō and Rotorua that weekend will be detoured via SH1 and SH30 through Ātiamuri while SH5 is closed. Drivers should be aware that Broadlands Road, a common alternative route between Taupō and Rotorua, will also be closed as it is on the cycle route.    

Approximately 5000 competitors and supporters are expected to travel from overseas to take part in the event, with most of them expected to arrive in Taupō from this weekend onwards.

SH1 Desert Road to close 13 January 2025

SH1 between Tūrangi and Waiouru – including the Desert Road – will close for approximately 2 months from Monday 13 January 2025.

This is a week later than we originally scheduled as we’re trying to reduce the impact on people’s summer holiday journeys. 

We have had a lot of feedback from people asking why we have to start this work in January and why we don't look at doing it in February and March. 

Looking at the Desert Road Weather Station data for January, February, March 2024 the average ground temperatures were below 13 degrees for up to half the available working days in March, whereas in contrast in January and February there were only 1 to 2 days where average ground temperatures dropped below this threshold. 

We need the ground temperature to remain above 13 degrees for sealing to be successful. 

We also need to allow time between laying a new chipseal surface and the start of ground frosts to ensure it has been well embedded.

Going back to the weather station data, we can see that overnight minimum temperatures are starting to drop below zero across the Desert Road in March meaning the possibility of ground frosts, something which rarely occurs in January February. 

Of course every season is different but we can only plan what is considered typical and clearly in regard to the temperature limits that we need to work with, March carries far more risk  than January and February.

Closing the road for this length of time isn’t something we are doing lightly. By having complete closures we can complete our work more efficiently and safety. We can combine work requried, for instance, in this closure we are also replacing the deck of the Mangatoetoe-nui Bridge at the same time as doing the roadworks. We can use more invasive construction methodology, which would not be possible under stop/go traffic management – meaning SH1 will be quickly brought up to a higher standard. 

SH1 Desert Road closure detour

When the Desert Road is closed the detour will be (from north to south) – SH41, SH47, SH4, SH49 and back to SH1. The detour will add about 35 – 40 minutes to people’s journeys.

South of the SH1/SH47 intersection (the “soft closure point” – shown in orange on the map) to the beginning of our first worksite (south of the Tongariro National Trout Centre) remains open to everyone.

Additional signage will be placed at the detour points advising businesses beyond this point are still open. We need to advise the detour earlier to those on longer journeys so they can use the appropriate state highways. 

Southbound traffic will not be able to travel further south beyond Tongariro National Trout Centre.

The “hard closure” (black area on map) is from Tongariro National Trout Centre to the Desert Road gates near Waiouru. Within this hard closure, there will strict requirements before anyone can go into that area as there will be a multitude of machines and people working on the road at all times of the day and night.

This means the road is very restricted as to who can use it and those needing access to these sites will need to adhere to traffic management and be prepared for delays through the area.

SH46 will be open to give access to residents and businesses and those undertaking recreational activities in that area, but there will be no throughfare to or from SH1. 

Members of the project team are visiting Turangi and businesses and residents in the area next week to give more information to those working and living within the closures. If you want to talk to the team in person, please email us. 

Stakeholder Advisory Group

Thanks to those who joined us for our latest stakeholder advisory group meeting.  It was an excellent chance to catch up with people affected by our closures.  We even had a few laughs in amongst the serious talk about how these closures were affecting them. 

We are keen to hold more of these sessions in 2025, so please let us know if you want to be part of this.

More information

This work forms part of the government’s $2.07 billion investment into road and drainage renewal and maintenance across 2024-27 via the State Highway Pothole Prevention fund.

Please pass this on to others who may be using SH1 in the next few months and encourage them to sign up to this newsletter by using the subscribe button below.

For more information or any concerns on the SH1 Tīrau to Waiouru maintenance, please email us.

Please visit our website nzta.govt.nz/t2w