Editorial: Rolling out the repair work on potholed roads

A large programme of roading repair work is getting under way. Photo / Warren Buckland

Opinion

Over the summer Kiwi drivers will be in need of calm vibes, air con, and water in their cars because a lot of road repair work will be slowing them down.

A major programme of road maintenance, pothole repairs and resealing will be under way. About 2400 lane kilometres of state highways, or 10 per cent of the network, is to be worked on.

It’s occurring as debate over the state of New Zealand roads and the proliferation of potholes heats up again. Motorists pay road user charges, and potholes are an annoying and sometimes expensive issue, especially for people living in areas where repairs are slow to occur.

There have been positive strides made on roading this year: the new Cambridge/Hamilton stretch of State Highway 1 is faster and seems safer to drive on. But there have also been hundreds of complaints about car damage from potholes on several highways.

Opinions have been tossed around over whether high rainfall this year is the main culprit; if contractors are adequately on top of the problem; and if the number of freight trucks on the roads and the weights they carry are factors.

Waka Kotahi says rain is the main issue, “and we’re seeing these events occur more frequently now due to climate change”. A spokesperson said: “As vehicles drive over the ponding water, tyres create hydraulic pressure, forcing the water down into the pavement. Over time, as vehicles continue to run over the pothole, it’ll grow in size as weakened areas break off.“

Several extreme flooding events in New Zealand this year have caused extensive problems for affected residents and businesses with slips and limited access.

The wider pothole phenomenon is increasingly happening elsewhere in the world and looks likely to generally worsen in coming years.

The ACT Government in Canberra has blamed road damage on higher-than-normal rain, higher traffic volumes and more heavy vehicles. Australian Road Research Board chief executive Michael Caltabiano said more asphalt was needed for the roads which were mostly made up of the cheaper bitumen. The State Government’s planned work involves a 150 per cent increase in the use of asphalt.

In Australia, drones have been suggested as a way of more frequently monitoring roads for developing potholes to ensure quick road maintenance before they worsen.

New Zealand’s roads carry a particularly high burden of passenger and heavy goods traffic, thanks to generations of inaction over rail.

A better-developed modern rail network would be able to shift more freight and zip people around by fast train, as a viable alternative to the car and plane. Other countries are still introducing new rail systems. A high-speed rail route is gradually taking shape across Southeast Asia with input from rivals Japan and China.

AA road safety spokesman Dylan Thomsen said earlier this year that vehicle kilometres travelled in the 2010s had increased, including by heavy vehicles, adding to the stress on the roading network.

Waka Kotahi says a large part of the repair works will take place in the Waikato and Bay of Plenty.

“Our investment in the national maintenance programme through the 2021-24 National Land Transport Programme is increasing to $2.8 billion, including an estimated $300 million for emergency works. This is a 30 per cent increase on the previous three years (2018-21).”

Pothole repair could become a much deeper funding hole in the years ahead.