John Williamson: Why keep 80km/h speed limit on Brynderwyns?

A police officer checks motorists' speeds on the Brynderyn Hills soon after the reduction of the speed limit to 80km/h in 2010. Photo / File

ON THE ROAD

It's been almost 10 years since the speed limit over the Brynderwyn Hills was reduced to 80km/h.

Back then there was a huge outcry from those who liked to drive the curves of the "longest up-hill passing lane in New Zealand", and why was this cheap thrill being curtailed, some asked.

The facts at that stage were that, in the previous five years, there had been 79 serious crashes, with three fatals on the northern side. They averaged more than one a month. Loss of control on bends and crossing the centre line were the main causes, which were exacerbated by a shower of rain.

The AA's position on reducing state highway speed limits back then, was generally supportive based on crash evidence, but that this signalled the need for engineering improvements to deal with the crash causes, so that the open road speed limit was restored.

Since then about $18 million has been spent in realigning the northern side, installing median and side wire rope barriers along this side and creating a lookout point to the ocean view countryside. I recall a prominent local councillor commenting with derision about that ridiculous cost.

Since being installed several years ago, the centre and side wire barriers on the northern side of the Brynderwyns have helped reduce the number of fatal or serious crashes. Photo / File

It now looks and feels like the safest stretch of road north of Auckland and the lack of fatal and serious crashes reflects that. The engineering upgrade has occurred so why then, is there still an 80 km/h speed limit on that stretch of road?

Curiously, this question was asked by two different people at two different forums last month. The Regional Transport Committee on February 11 and the AA Northland annual general meeting on the 18th.

The answers suggested there was a case for a review, and it was interesting that the mood of the meetings was not categorically in support of increasing the speed limit.

The north side of the Brynderwyns has long been a crash hot spot. Drivers were focused on the difficult driving up the south side, seemed to admire the vista at the top, then somehow relax and lose concentration.

If the road curve is slightly out of context, or wet, or you are going too fast, then you were in trouble.

Now, when you reach the top, you are immediately directed by the centre wire rope barrier and you can't really admire the view. The wire rope barriers focus your driving and you can pull off for the view further down.

Side and centre wire barriers reduce run off road and cross centre line crashes. They act by catching vehicles that leave their lane before they hit something less forgiving - like other vehicles or roadside hazards. Their flexibility cradles the vehicle, absorbing impact energy, slowing the vehicle and re-directing it to the highway, while the vehicle remains upright.

The Brynderwyns centre and side barriers have not stopped drivers making mistakes. The barriers have been hit an average of 15 times a month and the crashes are not necessarily reported.

The volunteers at Waipu Fire Brigade are able to sleep easier, though, knowing the Brynderwyns are not the killing fields they used to be.

The question remains, though, now that this is the safest stretch of road north of Auckland, is the 80km/h speed limit still justified?

Many drivers pass me as I drive at 80km/h on this road and, apart from being over the speed limit, they are not driving unsafely. The new road can sustain a higher speed limit. But 80km/h is too high for the southern side.

So is it smarter to leave the Brynderwyns all the same for the sake of an extra 15 seconds travel time?

The self-explaining road philosophy is that the road itself should send a message about the safe speed to drive it. Time to start the conversation and have that review.

• John Williamson is chairman of Roadsafe Northland and Northland Road Safety Trust, a former national councillor for NZ Automobile Association and former Whangārei District Council member.