The main entrance of 40 Prospect Park West is, unsurprisingly, on Prospect Park West.  However, for those using Lyft that uses OSM, the car is directed to make a right turn on Garfield Place.  There is a side entrance to the building on Garfield Place that is used by a single doctor's office.  Both options are listed on OSM, but the default should be the main building entrance, not the doctor office.  For patients of the doctor, there is signage in the lobby area to use the side entrance.  