Bus bathroom design

Today, a quick note that combines two of my favourite topics: bathrooms and user interface design.

I recently ended up travelling by bus from London (Ontario) to Toronto. For various reasons, I also had the chance to use the washroom on this bus.

The washroom had a great UI innovation: when you lock the door, the light comes on. Why is that so great? Well, think about it like this:

1. You never want to use the washroom in the dark.^(*)
2. You never want to use the washroom with the door unlocked.
3. It's hard to tell sometimes whether you have the door locked.
4. It's easy to tell whether you have the lights on.
5. It's hard to remember to turn off the lights when you're done.
6. It's easy to remember to unlock the door when you're done.

This simple design innovation feels great. You go into the washroom: oh, great, another screwy industrial bathroom door lock design. I wonder how I lock it. Let's see... click - and the light turns on! It's really satisfying, because the user gets instant feedback that they have accomplished what they wanted. Even though you weren't even trying (yet) to turn on the light, the fact that it turns on is an instantly understandable signal that you have made something happen, and since you were obviously fiddling with the door lock, you can easily assume that what you made happen was the locking of the door.

Side note

Actually, there's a tiny little night-light thing that makes it possible to see even when the light is off. This serves two purposes: on your way in, you don't get obsessed with turning on the light (which would be frustrating, since there's no light switch). On the way out, you can unlock the door without immersing yourself in total darkness.

Smart!

Footnote

^(*) In Spain, almost all washrooms seem to have motion-sensitive lights. Basically, this means that if you want light, you have to wave your hands around occasionally while you poo. While traveling there I developed a love-hate relationship with these motion sensors. Briefly: lights that turn themselves on and off based on a vague concept like "motion speed beyond a fixed threshold" and "no motion for a fixed amount of time" are exactly the opposite of delightfully immediate user feedback. And secondly, pooing in the dark is an interesting experience that in many cases beats waving your hands around every 30 seconds.