I’m not fully sure the circumstances this sign is elucidating, but I can tell you I won’t be riding my bike here, that’s for sure.
@superbetsy I can relate to that sign. 🚲 No wheel was lost! The front wheel just turned 90 degrees because of the tram rail, with more force than the handlebar was tightened. I get that if it hasn't happened to you (yet), you might not recognize the sign. 😆