This bulletin was prepared before the Eightieth Congress, Second Session, convened in 1948. Printing was interrupted in order to include, because of their importance, the Federal-aid Highway Act of 1948 and an amendment to the Regulations for Carrying into Effect the Provisions of the Federalaid Highway Act of 1944. They appear immediately following the table of contents but are not referenced in either the contents or the index; nor are other acts or regulations, affected by them, annotated accordingly.