A train that ejects passengers at the right station
A few years ago, I took the Bart from Mission to to Embarcadero every morning. The image above shows what it felt like. Squashed between morning commuters, I came up with a fix. Note how people tend to flock around the doors. The rest of the train is completely empty.
What if instead it could look like this?
That's a conveyor belt. It takes up half of the train's width, and is perfectly timed with the train's current progress on the current line.
The destination stations are marked on the conveyor belt.
You can choose to take a seat if you're going far. Just keep an eye on the conveyor belt and hop on as soon as your station comes rolling past your seat.
Finding your spot
The whole thing starts before you board the train. Walking towards the platform, signage guides you toward the right door to enter, the one that will take to you to the right spot on the conveyor belt.