Drivers around the Wellington region should watch out for "summer ice" on the roads over the next week, the NZ Transport Agency (NZTA) says.

"There is some rain forecast for Wellington tomorrow and next week, and after a number of hot summer days we may start to experience slippery road surfaces, known as summer ice," regional transport systems manager Mark Owen said.

"We know that even a small amount of light rain can make our roads slipperier. In fact, it can be more dangerous than heavy rain because grime and exhaust particles that have built up on the road take longer to be washed away.

"The combination of light rain and grime creates a slippery film on the road. The film is invisible so drivers should not assume it isn't there just because they can't see it."


Anyone driving in the rain or on a damp road tomorrow and next week should take extra care, he said.

"Drivers should keep safe in these conditions by increasing their following distances and reducing their speeds.

"It's also a good idea for drivers to check the tread level and air pressure on their tyres. Properly inflated tyres with good treads are always a must for safe travel, but even more so in wet or slippery conditions."