Anyone who has spent a Saturday laying a concrete pad for a carport or a backyard barbecue is likely to be engaging in a bit of headscratching over Prime Minister John Key's plans for a 3000km concrete national cycleway.
The PM says the idea, which came up at the jobs summit, will cost $50 million, according to "a rough, back-of-a-piece-of-paper determination". Rough, indeed. Perhaps Key has not done a lot of concreting and should have asked to borrow a concrete contractor's piece of paper.
Getting fleets of ready-mix trucks up the top of the Rimutakas, never mind barrowing the grey sludge through the undergrowth to the boxing is a pricey undertaking. The cost of the Te Araroa walkway, which was largely a process of designation and called for minimal construction, will top $10 million by the time it is finished.
It could be, of course, that Key wants the cycleway to run, like a suburban footpath, alongside the highway, which rather undermines its amenity value. Hardy souls daily brave city traffic to commute on two wheels, but cyclists do not head into the countryside to ride next to speeding highway traffic.
In the end, the cycleway is one of those ideas that sounds much better than it is. Ours is a fine country for cycling and the popularity of the Central Otago Rail Trail attests to the tourism value of cycleways.
But we should not build a cycleway for the sake of doing so. Let's choose the parts of the country - most in hard-pressed provincial areas - that would be attractive to cycle through or across, and build cycleways there. A concrete path the length of the country is a daft idea.