US Route 42 is one of America's diagonal routes, running from Louisville, Kentucky, northeast to Cleveland, Ohio, in the same way that Interstate 71 does. Despite its even number, it's usually signed with "north" or "south" banners--but its path is so close to that perfect 45-degree angle that it's really difficult to decide whether it deserves an even number or an odd one! US Route 42 usually parallels Interstate 71 to the northwest, connecting to all of the same major locales as Interstate 71, with one exception: US Route 42 flanks the western and northern sides of Columbus, rather than passing through it. The southwestern end of US Route 42 is concurrent with US Route 60 in Louisville, at US Route 31E. The northeastern end of US Route 42 is at the Cleveland Public Square, in the heart of downtown Cleveland (also the western end of US Route 422). The route ends concurrent with US Route 6, US Route 20, and Ohio State Route 3.