The reflectors make the arrows easier to see at night. If you're traveling in the direction you're supposed to be going, you see white reflections. If you're traveling the wrong way, you see red ...

If you're a driver (or even a passenger), you've seen them: small color-coded plastic markers in the center, or sometimes at the edge, of the road. They have various names; in the U.K., you'll ...

The reflectors make the arrows easier to see at night. If you're traveling in the direction you're supposed to be going, you see white reflections. If you're traveling the wrong way, you see red ...