On January 2, 1974, President Richard M. Nixon (above) signs
the Emergency Highway Energy Conservation Act, setting a
new national maximum speed limit.
Prior to 1974, individual states set speed limits within their
boundaries and highway speed limits across the country
ranged from 40 mph to 80 mph.
The U.S. and other industrialized nations enjoyed easy
access to cheap Middle Eastern oil from 1950 to 1972,
but the Arab-Israeli conflict changed that dramatically
in 1973.
Beyond fuel savings, the NMSL significantly lowered the
national traffic fatality rate, becoming a road safety tool
as well.

Lt. Gen. Benjamin O. Davis, Jr., and NHSA Administrator
Joan Claybrook, President Jimmy Carter and Secretary
of Transportation Brock Adams, unveiling a promotional
speed limit poster in the Oval Office, 1977 (Jimmy Carter Presidential Library/NARA)