Yesterday I attempted to build a route for a wheelchair activity and discovered that it was routing me up and down the stairs for a pedestrian bridge (rather than using the adjacent ramps). Bike and other rolling activities successfully routed up the ramps. I also tested this in a couple of nearby locations and it repeated the same result: wheelchair routed up the stairs, and bikes/handbikes routed around. 

See below. First location is (37.8347523, -122.2910888) and second location is (37.8985159, -122.2669583)