The tram runs on a wide concrete strip in the middle of 40th Street.  The crossing has asphalt, then concrete, then asphalt.  I didn't see an option to tag the surface as mixed materials so I had to choose one.  I picked concrete because I guessed that concrete would be more of a hazard to the blind of wheelchair-bound, should it fall into disrepair.

I would be grateful for your advice about how to handle this sort of thing.