It’s best to drive by the street which is used for bus and taxi parking for the convention center that runs along the 648
Frankfurt am Main like many other German cities have common Streetwalker areas or zones where it’s common to find them. Usually evenings they’re situated close to the Frankfurt am Main Messe of convention center to take advantage of the tourists and convention attendees. Your milage may vary from normal gals to crack addicts so care should be taken.
Note it’s the 44 on the blue side of 648