Is this what bored people do with their free time? This is kind of amazing in a really weird way.
Look at that fancy new wheelchair ramp in the center of the bus!
This bus system in Adelaide, Australia allows normal vehicular busses to transfer onto a rail system. The system here is known as the O-bahn and has reportedly been in use since 1986.
Here's one more video.
Speed. It's all about speed when you're on a bus. And this method of bus boarding (while not unique to Vancouver) is one very smart way to speed the process up. Because we all know there's always somebody holding the line up at the front.