Portland has been installing countdown displays at stoplights. But sometimes when they count down, nothing happens—the light remains green. Why can't they sync with the yellow light, like they're supposed to?

—Counting the Seconds

Let's take a moment to pity the reasonably intelligent people who actually run the world.

I don't mean the robber barons of Wall Street; those guys are just as stupid as you and me. I mean the poor bastards who master epidemiology or civil engineering, hoping to keep the world's trains running on time, only to run smack into the vast, cowlike stupidity of the common man.

Take the old-style "Walk/Don't Walk" signal, invented decades ago to keep you from blundering into traffic.

On "Walk," you walk; on "Don't Walk," you don't. Finally, a flashing "Don't Walk" means keep walking if you've already started, but if you're still on the curb, stay put.

How hard can that possibly be? Well, studies show there's a stubborn 15 percent of the populace for whom that flashing "Don't Walk" signal might as well be Gödel's incompleteness theorem: They just. Can't. Get it.

Some of us might greet this news by muttering "Go Darwin" and looking forward to a moron-free tomorrow. But the traffic-safety community, ever earnest, responded by inventing the putatively idiot-proof countdown pedestrian signal.

And now, Counting, you and your cud-chewing brethren come along refusing to understand even this simplified version. It's depressing.

To (pointlessly) clarify: the countdown is there to tell pedestrians how long they've got to stagger across the street. It's not for cars. Depending on the width of the roadway, whether there's a left-turn lane, etc., the countdown's zero may or may not sync with a yellow or red light.

Either way, if you're driving, just ignore the timer (like you do every other traffic-control device) and you'll be fine.

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