When it comes to the rules that help keep us safe while we drive, most likely the greatest cost-and-simplicity to benefit ratio has to be painted lane lines. They are just paint, but they make driving much safer and more manageable than it would otherwise be. If you don’t believe me, the next time you end up on a stretch of new road that doesn’t have lane marking painted yet, note how quickly everyone begins to start panicking and driving like loons. The history of these simple lines goes back further and is more complicated than you’d guess, and this video does a great job of explaining things.

This is a video from The History Guy, an earnest, professorial fellow who looks and sounds pretty much exactly like what you’d expect someone calling themselves “The History Guy” would look and sound like. Here, take a break and watch