New York’s Subway cars used to be covered in graffiti – it was as much a part of the city as Times Square. But since the late ’80s, they’ve been free of vandalism:
Systemically, train line by train line, Gunn took the subways off the map for graffiti writers. While they were fixing it, they didn’t allow any graffiti on it. If graffiti artists “bombed” a train car, the MTA pulled it from the system. Even during rush hour.
They still get vandalized but with increasing fines and how quickly they get cleaned, the "art" is dying.