He said the graffiti vandals in part choose dangerous locations for their "tags," as they're known, because workers will be reluctant to go up there to remove them. He said vandals reach some of the locations with ladders or small ledges that may not be readily apparent as you're driving by. "They know what they're doing."
Then there's the thrill of not only risking arrest, but death. On the Internet, I found stories about daredevil graffiti vandals killed by a train in Pittsburgh and a 35-foot fall in Cincinnati. In San Jose, where railroad bridges over freeways were frequent targets, officials talked about erecting barriers, but they acknowledged that any barrier can be breached. "I've heard of these guys using mountain-climbing equipment," one official said.
Pittsburgh officials were plagued for years by a daredevil graffiti vandal known as "Mook." When city crews began cleaning up his messages, he switched to hard-to-reach places like tall bridges and highway overpasses.