<P> The National Maximum Speed Law ( NMSL ) in the United States was a provision of the Federal 1974 Emergency Highway Energy Conservation Act that prohibited speed limits higher than 55 miles per hour ( 90 km / h ) . It was drafted in response to oil price spikes and supply disruptions during the 1973 oil crisis . </P>
<P> The National Maximum Speed Law ( NMSL ) in the United States was a provision of the Federal 1974 Emergency Highway Energy Conservation Act that prohibited speed limits higher than 55 miles per hour ( 90 km / h ) . It was drafted in response to oil price spikes and supply disruptions during the 1973 oil crisis . </P>
when did they change the speed limit to 55
when did they change the speed limit to 55
1974
1974