John Williamson: Let's have a closer look at the cause of the pothole problem

We need to go hard on the problem of lack of money and good road building material, and go easy on the people. Photo / Michael Cunningham

OPINION

It's been a wet winter, our roads are pitted with potholes and everyone is moaning - rightly so.

Many of our roads were built to meet the needs of previous generations, are made from substandard material, have had a serious lack of maintenance over the years and have been pounded by 44-tonne loads they were never designed for - and then came the rain.

It's not fair, though, to point the finger at the road makers. No one goes to work to do a bad job and the gangs that create and maintain our roads do that with insufficient funding resources and take pride in what they do.

We need to go hard on the problem of lack of money and good roadbuilding material, and go easy on the people.

That said, though, winter does bring out the worst in our roads and potential compensation for damage to vehicles from our roads was a Regional Transport Committee agenda item this week. There's some irony in that.

To be clear, Waka Kotahi won't compensate you for pothole damage. But what emerged from the meeting is that Northland, with just three per cent of the nation's population, has almost 15 per cent of the national pothole compensation requests. Who says we haven't got the worst roads in the country?

There's been some pretty significant media coverage about the state of Northland roads, and the lack of deferred maintenance funding to bring them up to a reasonable standard.
The Facebook posts and public outcry need to go on, but at the same time let's have a closer look at the cause of the problem, and how we can direct our opprobrium that way.

It's a no-brainer that our road condition is not caused by cars, bikes, pedestrians or public transport – it is heavy vehicles that cause our problem.

It is an internationally held maxim, which has been generally accepted for the last 60 years, that the relative stress on our roads by different vehicles is the Fourth Power Law.

Winter does bring out the worst in our roads Photo / NZME

This holds that the stress on the road is greater, the greater the axle load of the vehicle in question.

This stress increases proportionately to the fourth power of the axle load of the vehicle on the road. The calculation evolving from this indicates that a 44-tonne, seven-axle log truck and trailer unit causes 2550 times more stress on the road than my 1700kg car, each time it passes.

When you consider the number of logging trucks on our fragile roads, compared to cars, then it is no wonder that our roads are pounded to death with that differential in stress.

But this is not about bagging logging trucks. They pay road user charges (RUC) based on a relatively equitable formula involving axle numbers and weight, except for two things.

Logging trucks piggyback their trailers back from the port, avoiding paying the RUC for the trailer on that part of the journey, and secondly, there is no evidence of the RUC being repatriated to the roads that they travel.

Relatively, logging trucks pay their way but it's the forest owners that don't.

These are the mostly distant and offshore investors with no interest in their communities. Their plantings have cleaned out the countryside of people, services and food production, creating sporadic employment but taking the profits and carbon credits to other destinations. They pay minimal council rates to maintain the roads they destroy.

Wairoa District Council has had enough of that and has introduced a four-times differential on the general rate on forestry land use, to fund the impacts of afforestation on the community and roading infrastructure. This means Wairoa District foresters pay twice what other commercial properties pay on their property value and over five times what other rural properties pay for most

council services. This approach has been validated by the High Court as being justified by forestry's relative impact on community well-being. Wairoa expects to raise an extra $400,000 from forest owners to balance up its roading budget.

Wairoa District Council has led the way with a general rate differential and opening the opportunity for other road-controlling authorities in their rating reviews, to ensure that forest owners pay their way in respect to local roading costs.