The evidence from overseas, and surely just common sense, says that reducing speed limits will reduce the severity of crashes. And on many occasions, enough to prevent a driving error from becoming a crash. At 80km/h, there's more time to get out of the way of someone else's mistake or poor driving.
Speed isn't the only factor, of course. Better, straighter, wider roads do make a difference. As do wire median barriers, which we need far more of in Northland.
The issue, though is cost, especially for building new and better roads. Maintaining the ones we've got is already a problem because of ballooning expenses.
So it was interesting what Ken Rintoul, a board member of Waka Kotahi between 2019 and 2021, had to say in this paper a few weeks ago.
He said reducing the speed limit to 80km/h had been discussed when he was on the board as one way of reducing roading costs.
That makes sense. If the budget's not there to fix every roading issue in Northland, and costs are increasing, then other strategies are needed to improve safety. Reducing the speed limit doesn't cost a lot of money. A bit of public consultation and some sign changes.
The problem is, this is not the way things have been done previously. More and better roads, whatever the cost to taxpayers, has been the mantra for so long. Which reinforces the notion that travel times on the open road should be getting quicker, not slower.
Dropping the speed limit to 80km/h goes against expectations that have been built up over some time.
Nevertheless, I can see a likely scenario that could be a palatable compromise. Have an 80km/h default speed for Northland, but identify the best stretches of road (especially on State Highway 1) that can be driven at 100km/h. Make 100km/h the exception, not the rule.
On most Northland roads, it's impossible to drive safely at 100km/h anyway. Most of us already adjust our speed accordingly.
To further sell the idea of a reduced speed limit, there are other positives to be factored in.
Travelling at 80km/h on Northland's winding and hilly roads will mean less accelerating and braking. A more constant speed will be maintained, resulting in less fuel usage.
Aggressive driving on twisting roads chews up petrol. Calm, steady driving at 80km/h, involving less foot shifting between accelerator and brake, would be like a forced saving scheme.
With petrol prices approaching $3 a litre, this wouldn't be a bad thing.
Maintaining a steady and lower speed also means less carbon coming out the exhaust, from trucks especially.
To meet our climate change targets, we either have to cut back our gross carbon emissions or purchase carbon credits overseas. Buying carbon credits is shaping up to be expensive for this and future governments. That's money that could be better spent on public transport or railway lines in this country.
I'd rather see the money go towards the infrastructure we'll need in a post-fossil fuel future than frittered away on carbon credits overseas.
An 80km/h speed limit on most Northland roads wouldn't just be about reducing serious injury and death.
It's also about public spending priorities in a world entering a period of extreme resource constraint, combined with the urgent need to do something about global warming.
Taking a wider view, an 80km/h speed limit doesn't look like the worst decision.
The inconvenience (even to transport businesses, where time is money) needs to be measured against what would be gained.
Slowing down to feel safer on our roads, as well as saving us money at the pump or collectively through our taxes, seems like a reasonable exchange.
