OPINION:
A string of new motorways north of Wellington are cursed - they all have to be ripped up for repairs either before they’ve opened or just a few months afterwards.
The roads are Transmission Gully, the Mackays to Peka Peka expressway, and the Peka Peka to Ōtaki expressway.
The countdown to Christmas has become a guessing game. Last year Wellingtonians wondered whether Transmission Gully would open in time for the summer holidays (it didn’t).
This year we are wondering whether the Peka Peka to Ōtaki road will open in time for the festive season (it might, but it’s uncomfortably close).
I don’t even have much of a vested interest in these roads, since I hardly ever drive on them.
As far as I can recall, the only time I have ever driven on Transmission Gully was during a media tour when it opened. I find State Highway 2 easier for trips north.
But I really do find it astounding just how difficult it is to build a road on time that doesn’t leak, doesn’t have to be ripped up for repairs, and doesn’t end up with 14 potholes after a weekend of heavy rain.
It all started with the Mackays to Peka Peka expressway, which is an 18km four-lane road that takes State Highway 1 along the Kāpiti Coast.
It opened to traffic in February 2017 and was completed four whole months ahead of schedule, but it was too good to be true.
Parts of the expressway began leaking within months, with moisture breaching a seal between the road’s base and asphalt causing discolouration and surface issues.
Nearly all of the road had to be resealed as a result.
This was highly embarrassing and presumably remained top of mind for those building the other roads connecting Wellington’s northern corridor.
So, you can imagine what people at Waka Kotahi NZ Transport Agency must have been thinking when independent inspection reports showed Transmission Gully was plagued by flawed chipseal and water seeping through the road’s surface before it even opened.
Luckily these were separate problems from the leaks discovered on the Mackays to Peka Peka road. They did, however, still result in parts of Transmission Gully being dug up.
More trouble with the road’s surface has emerged since Transmission Gully finally opened at the end of March this year. I’m not an engineer, but I’m pretty worried.
Earlier this month water carts were spotted on the road to keep it cool and stop something called “flushing”- a phenomenon caused by bitumen seeping up through the layer of chipseal on top of it.
It can mean the road becomes sticky and car tyres end up pulling the bitumen further into the chipseal. Apparently, some flushing is expected in the first year or two of a chipseal road opening.
But remember that chipseal defect that had to be fixed before the road opened? Yes, that’s right, that defect was flushing.
The weather then changed later in November and we had a weekend of heavy rain, which caused 14 potholes on Transmission Gully.
I understand roads need maintenance but surely that many potholes is ridiculous and totally unacceptable for a $1.25 billion road that only opened eight months ago.
If Transmission Gully is struggling with the weather now, I don’t know how it will cope in the height of summer or the more extreme conditions climate change will bring.
It doesn’t end there. Now we have the Peka Peka to Ōtaki expressway which may or may not open by Christmas after having already been delayed twice.
It doesn’t help that thousands of tonnes of asphalt have already had to be ripped up after problematic pockets of air were discovered in the road.
We should know within the next couple of weeks whether the road will be open in time for people heading off on their summer road trips.
Transport Minister Michael Wood was asked recently whether he was confident the road would open by Christmas as planned.
He said Waka Kotahi was working exceptionally hard and as with all big transport projects that happen in the open air, it depended on how the weather played out.
Well, last weekend the rain was so bad in Wellington that slips closed parts of State Highway 59 in Porirua and State Highway 2 in Lower Hutt.
It reinforced the need for Transmission Gully as a more resilient road, but it didn’t bode well for getting the Peka Peka to Ōtaki expressway open on time.
There’s still one more road left to build to complete Wellington’s northern corridor and that’s Ōtaki to North of Levin.
Given the track record of the other motorways, I’m sure this next road will be anything but smooth sailing.
• Senior Wellington journalist Georgina Campbell’s fortnightly column looks closely at issues in the capital.