Weather-activated speed sign trial set to start on Kaimai Range


High-tech, weather-activated speed signs are being installed on State Highway 29 (SH29) over the Kaimai Range as part of an innovative NZ Transport Agency trial set to start this year.

Contractors have begun installing 22 variable speed signs on a 12 kilometre stretch of SH29 between the State Highway 28 (SH28) junction on the Waikato side, and Soldiers Road on the Tauranga side.

The variable speed signs, along with four web cameras, will be linked to a weather station at the summit of the Kaimai Range.

When adverse weather hits, the posted speed will be reduced based on the conditions.
All 22 of the signs are expected to be in place by mid-October and after the technology is tested onsite the trial will go live in November.

The Transport Agency’s chief safety advisor, Colin Brodie says the two year trial aims to encourage people to drive at safe speeds when rain, ice and fog hit the Kaimai Range.

“Our data shows that over 70 percent of the crashes on the Kaimai Range happen in wet weather, and that over 40 per cent of these were caused by drivers travelling too fast for the conditions,” he says.

“Despite the changeable weather on the Kaimai Range people still attempt to travel at 100km/h.

“The new signs will allow us to drop the speeds to 60km/h on the Waikato side and 80km/h on the Bay of Plenty in adverse weather.

They will also be used during road works or in the event of a crash when speeds may be reduced to as low as 30km/h.” 

The speeds will be enforced by police.

Mr Brodie says the Transport Agency is working closely with police and others to reduce deaths and serious injuries on New Zealand roads. 

“Our work to create a truly safe transport system needs safe roads, safe vehicles, safe road use and safe speeds,” he says.

“This trial aims to get people driving at safe speeds that are appropriate to the road and conditions.

“If it is successful, and there is a reduction in death and serious injuries within the trial site, it may be rolled out across other similar sites in New Zealand.”

Speed restrictions and shoulder closes will be in place on SH29 over the next six weeks while contractors install the signs and motorists should expect minor delays.

For more information about the trial go to: link)



How will it work?

The Transport Agency will monitor the weather station located at the summit of the Kaimai Range, receive weather alerts and have access to web camera footage. These will be monitored 24/7 and the signs will be activated in adverse weather and deactivated once it has cleared.

The trial length is divided into two zones (eastern and western flank) to account for differences in localised weather.  This will allow the speed limit reduction to be put in place for either the eastern flank or the western flank, or both, dependent on the weather conditions. 

What are the speed limits?

  • The speed limit from SH28 junction to the summit (on the Waikato side) will typically be reduced to 60km/h in adverse weather. 
  • The speed limit from the summit to Soldiers Road (on the Tauranga side) will typically be reduced to 80km/h.
  • The signs will have the ability to show a range of speeds from 30km/h to 100km/h in the instance of extreme weather or events such as road crashes or road works.

How long is the trial for?

This is a two year trial which will be regularly monitored to assess driver behaviour and compliance.

Are the speed limits enforceable?

Yes. The activated speed limits will be enforceable by Police and are not an advisory speed limit.

When will the trial start?

The trial will be in place in late 2015.