Do you really know what you're doing on the road? I doubt I'll ever meet an American driver who'd say no, but a frightening one out of every three people who've taken the Traffic & Road Sign Test have failed.

Me, I'm not surprised. Whenever there's a major storm in my neighborhood, a number of traffic lights go out and a nobody seems to know what to do. At least half of the drivers around me run the malfunctioning traffic lights — both directions. Genius. Naturally, the same people will then stop at a flashing yellow.

In case you didn't know — and if you drive, you should — a traffic light that's gone dark is always treated as a four-way stop, just as if there were stop signs there. Always. (It doesn't take much intelligence to figure out why.) A flashing yellow, on the other hand, means proceed with caution: not stop, not yield. A flashing red, though, does mean stop.

Unfortunately, too many drivers don't know such basic rules of the road, which include observing the most common of traffic signs, which should usually be pretty self-explanatory. The aforementioned Traffic & Road Sign Test, which I discovered through Neatorama, demonstrates this sad fact.

What do you think your score will be? Head over to USA Traffic Sign's site and prove it to yourself. Let us know what your score is in the comments below.