Ohio State Route 718 sprouts out of Troy toward the west, providing access to portions of western Miami County. On the southwest side of Troy, Ohio Route 718 splits from a southwest-bound Ohio Route 55 to provide a link to portions due west of town. Ohio Route 718 promptly crosses over Interstate 75 with no interchange (if you want access to/from the Interstate, use Route 55) to proceed due west to Pleasant Hill. The highway crosses Ohio Route 48 in Pleasant Hill and keeps going for a few more miles. The western end occurs at Ohio Route 721, just shy of the western county line of Miami County.
My photo for Ohio Route 718 shows the first westbound trailblazer at Ohio Route 55 in Troy. The curve in the photo to the left drops travelers on a westbound alignment out of town; Ohio Route 55 doesn't provide that, as it chooses to exit the town toward the southwest. This photo was taken in September 2017, on the way home from a visit to Columbus.