Nonfiction · Level 3 · 188 words
One Line, Many Windows
Original passage © Studio AM, written for Fluency.
At some banks and airports, customers no longer pick a line. A single roped path snakes toward all the counters, and whoever stands at its head goes to the next window that opens. The snake looks long. It is usually the faster and fairer design.
Consider the alternative: one line per counter. You must guess which line will move, and your wait depends on that guess. Service times are uneven (one customer needs thirty seconds, another ten minutes), and separate lines let one slow case trap everyone behind it while the next line drains.
The single line pools that unevenness. Nobody commits to one counter, so a slow customer delays the whole snake by a little instead of delaying a few people by a lot. And the rule people care most about (first come, first served) actually holds, because no one who arrived later can beat you by picking a luckier lane.
So why do supermarkets keep separate lines? Because a snake of forty people looks alarming at the door, even when it moves quickly. Stores sometimes choose the design that feels shorter over the one that is.
Source: Written for Fluency. Original passage © Studio AM, written for Fluency.