Sounds like a dumbed-down version of signs years ago that warned riders against "expectorating."
Big round signs showing a bike with a red slash through the middle warn riders away from many intersections.
In MotoGP, a white flag is used to warn riders of rain.
Just as officials in the high-crime 1980's warned riders to beware of chain-snatchers and pickpockets, so are they now suggesting that iPod users avoid standing out.
For instance, on Tuesday night, the L.I.R.R. warned riders that they might have long waits, watching full trains pass them by.
Back then, ominous signs warned riders: "It's too much to explain on a poster."
But in the early 1980's, mostly to try to prevent muggings, transit officials started a color-code system to warn riders away from entrances that were closed at night.
On February 13, 2009, the victim's family sued Disney for negligence in the ride design, failing to adequately warn riders, and not providing proper safety restraints.
Still, many drivers expressed sympathy for the men, with one saying he had developed a code to warn riders that the police might be on the bus.
Chastened, it has lowered its expectations for the next great storm, and it is warning riders to do the same.