More than a third of New Zealand’s busiest roads have been identified as being unsafe, according to a new study.

The New Zealand road assessment programme study KiwiRap analysed and assigned star ratings to 10,000km of the state highways across the country.

A special vehicle fitted with five cameras recorded video footage of the road surface, condition, camber, ditches and trees.

In terms of ratings 39% of roads received a two-star rating, 56% received three-star rating and only 5% received a four-star rating.

Of all the highways, 32 were deemed high risk. Auckland and Northland had the most high-risk highways, followed by the Waikato/Bay of Plenty region.

New Zealand Transport Minister Steven Joyce said NZ$11bn($7.8bn) has been committed to improving the nation’s state highways.

New Zealand Transport Agency said it will remove roadside hazards and undertake minor improvement measures to help increase the safety of the nation’s roads.