I believe this is a multi use crosswalk:
This particular one is in Vancouver where 2nd Ave turns onto the Cambie Bridge. Cars have a yield sign. The crosswalk has the normal pattern in the middle, but on the edges it has dashed lines. If it was pedestrian only, it would have solid lines. As many bikes use this intersection going both ways, it doesn't make sense to have them dismount. In this area there are several intersections that look like this, and as far as I can remember they are all on bike routes.
When I approach this intersection on a bike I always have my hands on my brakes in case a vehicle doesn't yield. I've seen enough cars run through it and/or stop right in the middle.