I agree that motor_vehicle=destination is a better tag here, however "Dangerous Passing" is definitely not a name. It is more a way for the town to discourage through traffic even though it is technically legal, because the alley does not have its own parcel. There are multiple other "Dangerous Passing" signs nearby, for example off of Tappan Street behind Star Market and between Beacon and Garrison. Also, the alley should connect to Corey Road since there is no obstruction on that side.