A New Zealand first road safety initiative harnessing weather and power technologies to combat one of the country's most dangerous roads will launch on Monday.
Twenty-two weather-activated speed signs have been installed on a deadly 12km stretch over the Kaimai Range and aim to reduce the number of crashes on the busy highway.
The 100km/h speed limit will be reduced during bad weather, based on the amount of rain and wind recorded by a specially-installed weather station.
In the past 10 years, nearly 70 per cent of reported crashes on the Kaimai Range have happened in wet or icy conditions.
The signs will link to the weather station at the top of the range and information will be sent back to the Auckland Traffic Operations Centre where the speed limit on display will be adjusted accordingly.