As an emergency response to the 1973 oil crisis, on November 26, 1973, President Richard Nixon proposed a national speed limit for passenger vehicles and a 55 mph (89 km/h) speed limit for trucks and buses. In response to Nixon's proposal, the National Maximum Speed Limit (NMSL) was enacted in the 1974 Emergency Highway Energy Conservation Act that withheld Federal Highway funds from States that refused to comply with provisions of the law, including a maximum speed limit of for passenger vehicles, an increase Nixon approved in signing the final legislation.
By 1987, fuel price increases had slowed after the OPEC Oil Embargo ended, and the limit was increased to , but the law would remain in place until 1995 as proponents cited reduced traffic fatalities and pollution.
While some Americans recognized a patriotic duty to reduce petroleum-based energy consumption during the embargo, the speed limit was disregarded by most motorists, and at least four states opposed the law."Rising Chorus Against 55-MPH Speed Limit," U.S. News & World Report. March 17, 1975."Speed Limit 55: Is It Achievable?" Report to the Congress by the Comptroller General of the United States. Washington, D.C.: General Accounting Office, February 14, 1977. Retrieved from https://www.gao.gov/assets/120/118193.pdf Actions ranged from proposing deals for an exemption to de-emphasizing speed limit enforcement. The NMSL was modified in 1987 and 1988 to allow up to limits on certain limited-access rural roads. Congress introduced legislation to repeal the NMSL which was signed into law by President Bill Clinton on December 8, 1995.
The power to set speed limits historically belonged to the states. Before the NMSL, the sole exception to this occurred during World War II, when the U.S. Office of Defense Transportation established a national maximum "Victory Speed Limit" of , in addition to gasoline and tire rationing, to help conserve fuel and rubber for the American war effort. Although it was disregarded by some motorists, the Victory Speed Limit lasted from May 1942, to August 14, 1945, when the war ended.Lynn Arave, "'Patriotic Speed Limit' was 35 mph." Deseret News, Salt Lake City, Utah, February 17, 2009. Retrieved from https://www.deseret.com/2009/2/17/20302452/patriotic-speed-limit-was-35-mph/ Immediately before the NMSL became effective, speed limits were as high as . (Kansas had lowered its turnpike speed limit from before 1974.) Montana and Nevada generally posted no speed limits on highways, limiting drivers to only whatever was safe for conditions.
1973—55 mph National Speed Limit
As of November 20, 1973, several states had modified speed limits: : Rhode Island, Maryland, Massachusetts, New Jersey, New York, Vermont, and Washington : North Carolina and Oregon California lowered some limits to . In late November 1973, Texas Governor Dolph Briscoe recommended adoption of a statewide limit. On December 4, the Texas Highway Commission, with a 3–0 vote, adopted this speed limit, citing unsafe speed differentials between the flow of traffic and people driving too slowly to comply with Nixon's and Briscoe's requests for voluntary slowdowns. The legality of the measure was questioned, and two Texas legislators threatened to sue to block the limit. By December 6, Texas Attorney General John Hill ruled that the speed reduction "'was in excess' of the commissioners' legal power," citing that a 1943 Texas Attorney General's opinion held that the legislature holds the power to set the statewide speed limit and the commission's authority was limited to changing it in specific locales where safety factors required lower limits.
On November 26, 1973, President Richard Nixon proposed a national speed limit for passenger vehicles and a 55 mph (89 km/h) speed limit for trucks and buses. Also proposed were a ban on ornamental lighting, no gasoline sales on Sunday, and a 15% cut in gasoline production to reduce total gas consumption by 200,000 barrels a day, representing a 2.2% drop from annualized 1973 gasoline consumption levels. Nixon cited scientific data showing that cars achieve maximum efficiency between and that trucks and buses were most efficient at .
The California Trucking Association, the largest trucking association in the United States, opposed differential speed limits on grounds that they are "not wise from a safety standpoint."
Enactment
The Emergency Highway Energy Conservation Act was a bill in the U.S. Congress that included the National Maximum Speed Limit. States had to agree to the limit to continue receiving highway trust funds. The uniform speed limit was signed into law by Nixon on January 2, 1974, and became effective 60 days later, by requiring the limit as a condition of each state receiving highway funds, a use of the Commerce Clause of the United States Constitution.
The legislation required speed limits on all four-lane divided highways unless the road had a lower limit before November 1, 1973. In some cases, like the New York State Thruway, the speed limit had to be raised to comply with the law. The law capped speed limits at on all other roads.
A survey by the Associated Press found that, as of Wednesday, January 2, 1974: 12 states already had maximum speed limits of . 9 states had maximum speed limits of . 29 states had to lower limits. That includes some states that voluntarily lowered their limits in advance of the federal requirement.
On May 12, 1974, the United States Senate defeated a proposal by Senator Bob Dole to raise the speed limit to . The was established as a uniform national speed limit when President Gerald Ford signed into law the Federal-Aid Highway Amendments of 1974 on January 4, 1975.
Safety impact The limit's effect on highway safety is unclear. Both during the time the law was enacted and after it was repealed, automobile fatalities decreased, which was widely attributed mainly to automobile safety improvements, owing to an increase in the safety of cars themselves, and the passage of mandatory seat belt legislation by all states except New Hampshire from the mid-1980s to the early 1990s."Traffic Safety Facts 2012: Occupant Protection." DOT HS 811892. Washington, D.C.: National Highway Traffic Safety Administration (March 2014, revised September 2014). Accessed from https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/811892 This decrease in fatalities from automobile accidents makes figuring out the actual impact of the law difficult. Although the vast majority of states reported fewer traffic deaths in 1974 compared with 1973, there were in fact three states where traffic deaths actually increased in 1974, 1975 and 1976, compared to 1973, notwithstanding the 55 mph (90 km/h) speed limit: Alaska, New Hampshire and Wyoming. National Highway Traffic Safety Administration (1977) "55 mph Fact Book," p. 12, Table 1.
According to the National Research Council, there was a decrease in fatalities of about 3,000 to 5,000 lives in 1974, and about 2,000 to 4,000 lives saved annually thereafter through 1983 because of slower and more uniform traffic speeds since the law took effect.Transportation Research Board. 1984. "55: A Decade of Experience." Special Report 204. Washington, DC: National Academies Press, pp. 31-34. Accessed from http://nap.edu/11373. Later, the National Academies wrote that there is "a strong link between vehicle speed and crash severity [which] supports the need for setting maximum limits on high-speed roads" but that "the available data do not provide an adequate basis for precisely quantifying the effects that changes in speed limits have on driving speeds, safety, and travel time on different kinds of roads." The Academies report also observed that on rural interstates, the free-flowing traffic speed should be the major determinant of the speed limit: "Drivers typically can anticipate appropriate driving speeds." This is due, in part, to the strong access control in these areas but also is an acknowledgement of the difficulty of enforcing the 55 mph (90 km/h) speed limit in these areas.
A Cato Institute report showed that the safety record worsened in the first few months of the new speed limits, suggesting that the fatality drop found by the NRC was a statistical anomaly that regressed to the mean by 1978. After the oil crisis abated, the NMSL was retained mainly due to the possible safety aspect."Statement on Signing the Federal-Aid Highway Amendments of 1974," President Gerald R. Ford, January 4, 1975. Retrieved from http://presidency.ucsb.edu/ws/index.php?pid=4750.
Insurance Institute for Highway Safety analysts wrote three papers that argue that increase from on rural roads led to a 25% to 30% increase in deaths (1/3 from increased travel, 2/3 from increased speed), citing Transportation Research Board. 1984. 55: a decade of experience. Special Report 204. Washington, DC., available for purchase online at while the full repeal in 1995 led to a further 15% increase in fatalities. In contrast, researchers at University of California Transportation Science Center argue that the interstates in question are only part of the equation, one also must account for traffic moving off the relatively more dangerous country roads and onto the relatively safer interstates. Accounting for this they find that raising rural speed limits to caused a 3.4% to 5.1% decrease in fatalities.
Fuel savings In 1998, the Transportation Research Board footnoted an estimate that the NMSL reduced fuel consumption by 0.2 to 1.0 percent. Rural interstates, the roads most visibly affected by the NMSL, accounted for 10% of the U.S.'s vehicle-miles-traveled in 1973, and although dropping speeds from 75 to 55 mph (120 to 90 km/h) reduces air resistance by nearly half, such free-flowing roads typically provide more fuel-efficient travel than conventional roads.Lexus IS250 2.5L 6cyl, Auto 6 speed Sedan, 5 seats, 2WD IS 250 Kraftstoffverbrauch kombiniert 8,9 L/100 km (innerorts 12,5 L/ außerorts 6,9 L) bei CO2-Emissionen von 209 g/km nach dem vorgeschriebenen EU-Messverfahren 2009 Lexus IS 250 6 cyl, 2.5 L, Automatic (S6), Premium http://www.fueleconomy.gov/feg/findacar.htm
Opposition and noncompliance Despite federal compliance standards mandated by Congress that no more than 50 percent of free-flowing traffic on 55 mph-posted highways exceed 55 mph from 1981 onwards, which required up to a 10 percent reduction in federal highway funding for states in noncompliance,Surface Transportation Assistance Act of 1978, Public Law 95-599, 92 Stat. 2689, pp. 2729-30. Retrieved from https://www.gpo.gov/fdsys/pkg/STATUTE-92-pg2689.pdf by the 1980s traffic surveys showed the NMSL was widely violated: The speed limit had very low compliance, contrary to the commonly accepted engineering practice that says that the speed limit should criminalize only the fastest 15% of drivers: From April to June 1982, speed was monitored on New York's Interstate highways, and an 83% noncompliance rate was found despite extreme penalties ranging from $100 (1982 dollars, equal to $ today) or 30 days jail on a first offense to $500 (1982 dollars, equal to $ today), up to 180 days in jail, and a six-month driver's license revocation upon third conviction in 18 months. In the fourth quarter of 1988, 85% of drivers violated the speed limits on Connecticut rural interstates. In 1985, Texas's State Department of Highways and Public Transportation surveyed motorist speeds at 101 locations on six types of urban and rural roads. It found that 82.2% of motorists violated the speed limit on rural interstates, 67.2% violated speed limits on urban interstates, and 61.6% violated speed limits on all roads. Western states began to reduce fines in the 1980s, effectively minimizing the impact of the 55 mph (90 km/h) limit: