What you call in your photos an "unmarked speed bump" looks more to me like an asphalt road patch/repair sealed at the perimeter. It could be the ambient lighting and/or the camera angle that disguises the bump, but, that's what it looks like to me, . . . . . from both directions.
The crack in your structural member has corrosion on/around what should be bare metal. How much time elapsed between the damage and the photo? Is that your truck/camper parked in the background across from the construction site?
How fast were you going when you hit this clearly visible "unmarked speed bump" located in a construction zone on a single lane high density downtown one way city street with a bike lane on the left and parallel parking on both sides when the damage occurred? What is the posted speed limit? I noticed that it was also about 3 parking spaces downstream from an uncontrolled crosswalk. (actually two)
Chum lee
