Where would we be without stop signs? These red, octagonal signs are a huge part of what organizes traffic across America, and they're a pretty universal signal to drivers that they should stop.

We’re all familiar with the classic red stop sign — from elementary school lessons on shapes and colors to the guidance of crossing guards and, eventually, driving on our own. But while it’s ...

You’d be hard-pressed to find an object simpler to use than the stop sign. Apples, for example, require more thought. You can ...