What happened to the 55 mph Federal speed limit?
There never was a national speed limit of 55 mph. The States determine speed limits. The impression of a “national speed limit” stems from the Emergency Highway Energy Conservation Act, which President Richard M. Nixon signed on January 2, 1974. In the midst of an energy crisis touched off by conflict in the Middle East and a subsequent oil embargo imposed by the Organization of Petroleum Exporting Countries that forced Americans into long lines at gas stations, the Act was part of a nationwide effort to reduce oil consumption. The law prohibited the Federal Highway Administration from approving highway projects in any State having a maximum speed limit over 55 mph. The States could retain higher speed limits if they wished, but at the cost of losing Federal-aid highway funding. As a result, all States complied with the legislation. The Surface Transportation and Uniform Relocation Assistance Act of 1987 allowed the States to increase speeds to 65 mph on rural Interstate routes without