It does exist (as an unimproved alleyway) and is the only access to certain lots (i.e. https://www.realtor.com/realestateandhomes-detail/703-Troy-St_Ypsilanti_MI_48198_M44625-73851), although it is currently illegally being blocked by neighbor's cars and other objects. 

It is on the official city street map:
https://cityofypsilanti.com/DocumentCenter/View/197/Boundary-Map-PDF

I believe there is a legal proceeding underway to clear Troy Street of obstructions. 

I believe it is in the public interest to document this public space notwithstanding its current obscurity.