The Auckland Harbour Bridge with two decks, as proposed by mayoral candidate John Tamihere. Image / supplied
COMMENT
Why did everyone think John Tamihere had flipped his lid when he proposed a new bridge over the Waitematā, to sit on the piers of the existing one?
Extra capacity for crossing the harbour is not a new idea. It's in the plans. Putting that extra capacity on the existing bridge isn't a new idea, either. Nor is adding rail, cycling and walking, all of which feature in Tamihere's proposal, along with two extra lanes for motor vehicles.
And a proposal to do all this at a fraction of the expected price of a new bridge or tunnels, shouldn't that be welcome?
But the way JT's bridge was received, you'd think he'd suggested a monorail. Actually, another mayoral candidate, Craig Lord, has proposed exactly that: a monorail network complete with harbour crossings, and that just got laughed at.
Monorails are the very definition of absurd transport plans, thanks to the Simpsons, but the reputation is undeserved because they work well in many parts of the world. But we'll leave Lord's idea for another day.
Tamihere didn't quite get laughed at but there was some sniggering. Mayor Phil Goff called it "total fantasy stuff and fundamentally dishonest to promise". He thinks it would cost at least $10 billion.
Tamihere himself says it would cost around $2 billion. He produced that figure by taking the square-metre cost (NZ$14,000) of a similar but much smaller bridge in Ohio, scaling it up to the size of his proposed bridge, adding 50 per cent to cover increased construction costs and then adding another 33 per cent for contingency.
Are the council candidates on the Shore excited? After all, there's a long-standing desire among citizens north of the bridge for a new harbour crossing. The answer is no: the response to JT's bridge has been almost non-existent. It's hard to find anyone even talking about it.
A new harbour crossing is already included in the Auckland Transport Alignment Programme, the transport agreement between Government and council. But it's on a 10-year horizon and Tamihere proposes to get it done in five.
Harbour crossings are in the hands of the NZ Transport Agency (NZTA). Transport ministers Phil Twyford and Julie Anne Genter received an NZTA briefing a year ago: at that stage, there were three options: road and rail tunnels, rail-only tunnels, and doing nothing. Most of the lobbying since then favours one or other of the first two.
NZTA is expected to announce its updated thinking very soon. Tamihere's bridge is unlikely to be on its list.
Strangely, he himself may not be fussed. On the campaign trail he no longer mentions the bridge, except to answer when someone raises it. He describes it as "just an idea".
He says he doesn't have the resources to do a full analysis, so he doesn't know how good the idea is. He wants to shake things up. Even if it turns out to be not great, it shows he's a guy who has ideas.
That leaves his adviser Will McKenzie shaking his head. McKenzie has been working on this particular idea since 2014.
He says while they've presented the proposal to transport officials in Wellington and Auckland, they didn't get anything more than blank stares.
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BUT STILL, is it a good idea? On cost grounds alone, doesn't it deserve serious attention?
As McKenzie explains, there's great value in using the existing piers. Concrete is expensive but steel is cheap, which is the reverse of how it was in 1959 when the bridge was built. That's why they made it smaller than it should have been.
There's value in using the existing bridge, full stop. Far fewer environmental issues. Although, if we're going to have a bridge at all, do we have to retain the ugliness of the original? Can't we have something beautiful?
The idea is to build the new superstructure next to the existing one, then slide the old one off and the new one on. Not easy, but not so difficult either. The University of Auckland's associate professor Charles Clifton, an expert in steel and composite steel/concrete construction, says it can be done.
McKenzie is quick to argue that it's not an 18-lane bridge, as commonly thought. There are 10 lanes for motor vehicles, four for rail, and four more for cycling and walking.
"Put it this way," he says, "how many lanes are there on Queen St? The answer is four. No one says it's six lanes because of the footpaths."
The bridge has two decks, with cars below and everything else above. Why expose cyclists and walkers to the elements? Why have two walkways? Those cycling and walking lanes don't seem thought through.
Why make the trains climb more steeply, to the higher level? McKenzie says these are tram-trains, capable of climbing a 6 degree incline, which is more than our current electric trains can manage. He says it's not a problem. There's also no problem for boats passing underneath.
But other problems remain. The proposal won't expand vehicle capacity. The bridge has eight lanes now, but the dynamic lane ensures it always has five lanes for peak traffic, with three going the other way. Effectively, it's already a 10-lane bridge.
The biggest issue is probably this: what happens to traffic, especially rail traffic, when it comes off the bridge at Northcote and Westhaven? To the north, rail lines and a whole lot more infrastructure will be required. To the south, the tram-trains can't feed into Britomart and the CRL, because that's going to be at capacity anyway. So they'll also need a new network to join.
McKenzie says yes, that network will be on-road in the central city and will replace the existing proposals for trams, also known as light rail.
They don't exactly say it, but this, not the bridge itself, is the most important aspect of the whole proposal. It calls for the existing electric trains to be supplemented and eventually replaced with a new fleet of tram-trains. They'll be able to run on the existing rail tracks, and on tram tracks with the same gauge set directly into the road.
One much larger, fully integrated, rapid transit network, connecting the city centre to the north, south, east and west, and to Hamilton, Tauranga and Whangarei.
It's a game-changer, dispensing with the debate about light or heavy rail altogether. But it also brings its own problems. For example: trains have doors that open at platform height; tram doors open at road level. This proposal means building platforms on the streets.
And it reopens the whole question of what the city's slowly growing rapid transit network will look like and where it will go. That, effectively, means the bridge won't happen in a hurry. It can't be built if there's no agreement to extend its reach. The last thing the city can cope with is more trains or more cars just pouring unplanned into the centre, without infrastructure to accommodate them.
There's another issue about Tamihere's bridge, which is to do with the transport plan it forms a part of. On the campaign trail JT may not mention the bridge but he invariably says he's going to stop "the war on cars".
What does he mean? He says he supports cycle lanes, but the "sequencing" has to be right. That's code for cycling comes later, we need more roadways for cars now. He condemns traffic calming measures and proposals to lower speed limits. Spending on public transport, he makes clear, can't be at the expense of cars.
The bridge is a look-at-me. But the transport plan it's part of is primarily about roads. It's entirely uninformed by climate change, safety, community and health considerations. It also ignores the central insight in transport planning all over the world: the realisation that supplying more roads means creating more demand for them, and therefore more congestion.
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