The Queue Chooser That Always Finds the Slowest Checkout

Introducing the Queue Chooser, a small round gadget that clips onto the handle of any shopping trolley. It has a friendly green arrow, a soft chime and a tiny screen that says Calculating. Wheel your trolley towards the checkouts on a busy Saturday morning, press the button, and the Queue Chooser studies every line in the shop, weighs up every basket and points you, with complete confidence, to the slowest one.

It never gets this wrong. It spots the customer who is about to discover a coupon from last spring. It knows which till roll is about to run out, which melon has no barcode and which shopper is going to pay for a loaf of bread entirely in small coins, counted out loud. The moment you join the queue it has chosen, the one next to it begins to move like a river, and the Queue Chooser plays its soft chime, as if to say well done.

The makers insist this is a feature. In early tests, shoppers who used the Queue Chooser reported a remarkable sense of calm. With the worst queue guaranteed, there was nothing left to worry about. They read the backs of cereal boxes. They made friends with the people behind them, who had also been guided there by a Queue Chooser. One man finished a whole crossword. A woman in the dairy aisle said it was the most relaxing shop she had done in years, and she had come in for milk.

There is a deluxe model with a second screen that shows how fast you would have gone in the other queue. Most owners switch it off after one trip. A travel edition works at airports, ferry ports and ice cream vans on the first sunny day of summer, and it has never once been beaten.

The real idea behind it

The joke works because almost everyone already feels they own a Queue Chooser. The other queue really does seem to go faster, and a little arithmetic explains a lot of it. If there are three checkouts open and they move at roughly the same speed, only one of them can be the fastest, so the odds that you picked it are about one in three. Most of the time, some other queue will beat yours, simply because there are more of them than there are of you.

Memory adds the rest. Nobody remembers the day their queue sailed through, but everybody remembers standing still while the stranger they arrived with reaches the car park. That is why many banks and post offices use one long snaking queue that feeds every counter in turn: there is only one line, so nobody can ever pick the wrong one. So the next time the next queue starts moving, relax. It was not you. It was just the numbers, and possibly a melon with no barcode.