PA 412 was realigned in Bethlehem to use Daly Avenue, 3rd Street, Brodhead Avenue and Broadway instead of 4th Street to reach PA 378 in the 1980s. In March 2012, a project began to widen PA 412 between Cherry Lane in Hellertown and Daly Avenue in Bethlehem.
PA 412 was modified in the 1980s to use a different route to reach PA 378, which involved using Daly Avenue, 3rd Street, Brodhead Avenue, and Broadway instead of 4th Street. A project started in March 2012 to expand PA 412 between Cherry Lane in Hellertown and Daly Avenue in Bethlehem.