"It's quicker to drive"

Start with the belief that does most of the work, because it's the one that feels like arithmetic.

Walking a mile at a brisk pace takes about twenty minutes. The NHS puts brisk at about three miles an hour, the pace at which you can talk but not sing. Half a mile is ten minutes. Now count the car, door to door. Find the keys. Get to the car. Start it, and if it's cold, wait for the windscreen. Reverse out. Drive, which on a half-mile trip through a town means junctions, a queue at the lights, and a speed that averages far below the number on the signs. Arrive. Do the parking dance, once round the car park for a space near the door. Park. Walk from the space to the door, which in a supermarket car park is often a hundred yards. Then the whole thing again in reverse, with the shopping.

I haven't seen a study that times this, so what follows is my reasoning and I'd rather you tested it than believed it. For half a mile in a town, the car's door-to-door time is usually between five and eight minutes each way, and the walk is ten. The car wins by a few minutes, not by the seven it felt like. For a quarter of a mile, the car often loses outright, because the fixed costs, keys, engine, parking, the walk from the space, don't shrink with the distance. And for a two-floor lift ride, the wait in the lobby is often longer than the stairs. Two floors is about thirty steps. A person who isn't running takes about forty seconds. The lift, with four people waiting and a stop on the first floor, takes longer than that as often as not.

A kettle is a fair comparison for two sentences. Nobody thinks it's quick to boil a kettle for one cup, because you're standing there for the whole of it. The car for half a mile is a kettle, and the reason it feels quick is that you're doing something for all of it, and the walk feels slow because you're doing nothing but walking.

Time it. That's the whole of this chapter's advice. Next time the keys come off the hook for a short trip, look at the clock as you pick them up, and look again when you're through the shop door. Then walk it once, and look at the clock the same way. The numbers are usually closer than you thought, and sometimes they're the wrong way round. Once you've seen that, "it's quicker to drive" stops being arithmetic and becomes what it always was, a feeling about the car.