What Henri means when he says: "you can create intricate lines that skip traffic jams and busy intersections, they no longer need to go directly from stop to stop" min:2:08? Maybe if a bus stop is empty, the bus will not stop ?
Also, the rain scenes (especially during the night) are awesome!
So I think he's talking about this. You can force buses to take a certain route without having to place a stop, this can be useful if the game calculates the default route through some busy area but you know a better route like a dedicated bus street or something.