'WE ARE a victim of our own success," said Coun Nick Wallis, Darlington Borough Council's "cabinet member" for highways and transport, referring to the apparently sudden realisation that one of the town's main roads might not cope with an extra 2,200 vehicles a day (one every 39 seconds).

With respect - which always means one is going to be at best blunt and at worst downright rude - it's not so much a case of being the victim of success as of the very common problem of not thinking it through. All these extra vehicles will be generated by a large distribution depot to be set up on what is, at least for the moment, the outskirts of town. Now, those of us who have sat through planning committees know that any development of more than the odd home or two is looked at from the point of view of the traffic it will generate.

This is a distribution depot. It distributes goods. Only Harry Potter can shift stuff from A to B by waving a wand. It's hard to believe that the whole thing slid through without a traffic impact assessment, given that acres of new housing, a school, a hospital and a sports ground have also sprung up just off this same road in the last year or so. Possibly the prospect of an estimated 700 jobs dulled the edge of perception. Now there's a thought; do the 2,200 vehicles include those in the 700 who will arrive by car, or will they be the subject of another surprise? The situation is being monitored. I hope someone is thinking it through pretty thoroughly.

Sadly this habit of not thinking it through, which has given rise to the law of unintended (or unexpected) outcomes, isn't confined to Darlington, or to local government. It can go from international level right down to household matters. Bob Geldof certainly didn't think through the prospect of a million protestors, however peaceful, descending on Edinburgh in the tourist season. But did the object of the demo, the G8 summit, ever think through the effect of holding discussions on the poorest of the world in one of the UK's poshest hotels? Still, if we thought it through properly, there might be unwanted repercussions hidden in the argument that summit and protestors alike should stay at home and send the cost of the jaunt to third world aid.

Nationally, I hope the deepest think tank in the business tackles this week's proposal to charge drivers per mile travelled, instead of taxing vehicles and fuel. I dread to think of the "unintended outcomes" lurking there.

On the domestic level, we've all done it. Before taking delivery of our car, we asked for a burglar alarm to be fitted, not thinking to specify one which marked switching on or off with merely a flash of the indicators. Result: we're lumbered with loud bleeps which drive us, and probably the neighbours, mad. We'll know next time. Damage limitation is usually easier on a domestic scale.