 Its eastern terminus is in downtown Willoughby at a signalized intersection where it meets US 20 and SR 174, the latter of which has its northern terminus at this same intersection.Located entirely within the western part of Lake County, SR 640 serves the northeastern Cleveland suburbs of Willowick, Eastlake and Willoughby.Known as Vine Street for its entire length, this stretch of roadway carried the designation of SR 288 prior to being re-designated as SR 640 in the early 1940s.