Motorists are being warned of slippery South Island roads after rain causes ice-like surfaces following hot days.
State Highway 83.
Photo: Krzysztof Golik, CC BY-SA 4.0
Transport Agency Waka Kotahi's lower South Island journey manager Nicole Felts told Morning Report the phenomena is known as "summer ice".
It occurs after extended hot days, followed by rain, which causes ice-like surfaces.
Listen to Transport Agency Waka Kotahi's lower South Island journey manager Nicole Felts speaking here
Felts warned even a small amount of light rain can make the roads very slippery in these conditions, and the problem was common.
"We do see it all over the country, but at the moment the conditions have lined up perfectly in the South Island.
"Because we've had such a long build up of all of that oil and grease and grime on the road it just takes a bit longer to be washed away, which means we have some slippery roads that people just need to take extra care on."
Felts said just like with black ice in the winter, areas on the road that are made more slippery by 'summer ice' conditions in the hot weather can't be spotted.
"What we advise is becuase the conditions have lined, that people drive to the conditions and take some extra care.
"Things like slowing down for your curves and bends, increasing following distance with the vehicle in front of you and braking nicely and gently, also really good to inflate your tires properly and check the tread level on them."