As in other nations, variable speed limits “zone” roads and highways according to local norms and contexts, from 15 mph in active school zones to accelerated speeds for limited access expressways (which, in some western states, had no limits). The energy crisis in 1974 allowed the federal government to fix 55 mph as a national maximum, raised to 65 mph in some areas in 1987. Yet, both individual drivers and advocates of states’ rights chafed under these limits, which soon became justified on the basis of safety as much as energy (given the growing popularity of large fuel-eating automobiles). Speed connotes freedom, whether in advertising, driving or western states’ attempts to get around these laws. In 1995 federal rules were repealed, allowing most states to adjust some highways to 70 or 75mph.