Driving to work these mornings, I pass a brilliant bit of traffic engineering. It is not the "park and ride" bus station they are building down at Barry's Pt, although I pass that too.
Somehow I can't believe Auckland commuters are going to drive to a suburban transfer station to make the rest of their journey by bus or train. Ask yourself, honestly, would you? Will you?
But there are proven ways to reduce the number of cars on the road. They do not involve bulldozers, big civic projects or outrageous rate bills. The one I see on weekday mornings is simply a line of kids walking to the local primary school.
Passing that primary school used to be a daily hazard. Nearly all the kids were carted to school in cars, as they have been now at most schools for about 20 years. I think it was the murder of the Christchurch schoolgirl Louisa Damodran that changed the nation.
Since her abduction, the roads outside primary schools before 9am and again in mid-afternoon have resembled the pits lane at Monaco.
Not any more in my neighbourhood and, I'm told, 70 other Auckland schools. That's the number that have adopted this idea they call the "walking bus". It simply means parents take turns at escorting their group of children on the walk to and from school.
The "driver" wears a sash, the kids are collected and dropped off at designated "stops" on the agreed route. Whenever I see it, the kids are trotting along three or four abreast as they would be on a bus and even the parents seem to be enjoying the walk.
So who thought of it? Probably every traffic planner at the Auckland Regional Council, years ago. But they never did it. The idea has taken off thanks to a different regional council - one that asks no money of us - Infrastructure Auckland.
Infrastructure Auckland nominally owns trading companies - notably the port - that were once run by the ARC. It is obliged to see that they are run strictly commercially and to distribute the accumulating profits to transport projects it assesses to be of most value.
When Infrastructure Auckland ran the walking bus idea through its cost-benefit models, it scored sky-high, far higher than the railway for which the ARC has jacked up the revenue it wants from us.
Little wonder, really, when you hear that fully 40 per cent of Auckland's peak-hour traffic is for education. Most of us notice how easily the traffic flows during school and university holidays.
You would think the ARC traffic planners, sitting in their eyrie in Pitt St with a stunning view of the cars entering Spaghetti Junction, would have noticed, too. Perhaps they did, but they didn't do anything about it.
And don't let them tell you that Infrastructure Auckland has the advantage of money to spend. It takes hardly any money to provide schools with signs, sashes and a bit of organisation.
So thank heaven (or the previous Government, to be fair) for a little bureau that is acting like a cautious but imaginative banker with its public fund. Does it have any other ideas?
Yes, says its transport manager, Roger Hill. At Rangitoto College they are testing a suggestion that student traffic could be substantially reduced by providing secure lockers in the school.
They suspect that many students come by car mainly because they are carrying so much gear which they daren't leave at school. You don't feel like humping musical instruments and sports gear, not to mention a bag full of books, onto buses. And you certainly don't walk or bike with the load.
So a little Infrastructure money is paying for lockers and security cameras, he says. If they entice students to travel lighter, who knows how much more of that 40 per cent of the traffic will be reduced?
And to my mind there would be a double benefit. One of the sadder sights these days are secondary school playgrounds on which pupils carry their bags around during breaks. Lockers with security cameras could solve that. And cameras, incidentally, do not need to be watched around the clock. A tape loop would seem a deterrent.
Hill gives credit for the Rangitoto idea to a parent and North Shore City Council member, Andrew Williams, which didn't surprise me. Williams is well known where I live.
He has come to wider attention by opposing the mayor's prayer before council meetings but he is not normally as churlish as that. He is a bundle of practical ideas, energy and community spirit. He is smart, dedicated and gets things done.
Sometimes you see him in the walking bus. I hope people like him stand for the ARC next year. By then the penny might have dropped that the rates bill is just the beginning of the price we will pay for this park-and-ride scheme. Most people haven't realised the half of it.
When the scheme was finally wheeled up to Infrastructure Auckland last year the assessors took one look at the patronage projections and said they could not justify the costs.
They sent the proponents away to get a revised business plan. The Boston Consulting Group was engaged: it found that to justify the cost of the railway there would need to be a tenfold increase in patronage, from 2.5 million passenger trips a year to 25 million by 2015.
The new business plan does not pretend the scheme can entice that number simply with the attractions of faster trains, reliable timetables and the glittering palace of Britomart. There would need to be a little bit of "traffic demand management" (TDM).
TDM, dear citizens, is road pricing, congestion charges, regional petrol taxes - that sort of thing. They are all down the track, as they say.
If the regional council was not hell-bent on running an old-fashioned railway, it might begin to think about why people use cars and how some simple, cheap ideas can make all the difference.