That sounds like a complaint to address to whomever designed that bus route, not to the drivers on the route? I'm sure the drivers don't enjoy that maneuver. (and sure, sometimes that's going to be unavoidable for any particular route...) Frankly, you sound a bit like an automobile driver, complaining about interstates and cutting across four lanes. On a bicycle it's easy to observe, plan ahead, and avoid the maneuver you've mentioned. For one thing, it always occurs in the same place! Also, it's great to be cycling behind a big vehicle as it vacates a lane: you've got first dibs on the free space.