It really looks like he did that on purpose. He looked at her, cranked the wheel one rev to the left, and held it there over the edge. There's also zero indication from smoke or tire marks that he ever came out of the throttle, much less hit the brakes. He rode that bus all the way down.
On the car rail, it looks like there's an ~18" concrete curb topped with a steel pipe system set into that concrete. Judging by the red car and the motorcycle there's a meter of vehicle stopping stuff. That's probably pretty standard. The little fence thing he took out last is just the pedestrian fence on the outside of the sidewalk, not really a "guardrail". There's a bunch or bridges in the US that have a similar setup that I think a bus would blow right through.