About: U.S. Route 111

U.S. Route 111 (US 111) was a U.S. Highway that extended from Baltimore, Maryland north to the Harrisburg, Pennsylvania area. It replaced part of the Susquehanna Trail, partially signed as Pennsylvania Route 4, and was in turn replaced by Interstate 83 (I-83). Portions of its pre-freeway alignment are now Maryland Route 45 and I-83 Business (I-83 Bus.). Other old sections in Pennsylvania are now unsigned Quadrant Routes or township-maintained roads. US 111 extended north to the Pennsylvania–New York state line where U.S. Route 15 now crosses it between 1928 and 1937.