I recently had the misfortune of riding on a really old CTA train car. The model in question, which probably dates back to the 1960s, was designed with doors that open into the passenger area of the car. In contrast, the newer trains use sliding doors that don’t interfere with passenger space.

The train I rode had a few empty seats, but I was tired of sitting down after a long time on an airplane. So I decided to stand, but kept running afoul of the train doors. I finally managed to get just far enough away from the doors to avoid them bumping my legs, but this made me wonder: why don’t the trains have some sort of visual indicator of where not to stand?

Even with the old train cars, it would be very easy to show passengers which areas to avoid. Just look at the path that the doors take when opening, and paint the floor below that area with a bright and obvious color, like yellow or red. Add a little bit of text like “Don’t stand in this area” or “Stand clear of doors”, and you’re all set.

Will everyone notice this the first time they ride the train? Probably not. But as soon as they get jostled by the doors a few times, you can bet that they’ll take notice and stay away from the painted areas.