National maximum speed law - wikipedia National maximum speed law `` Double nickel '' redirects here. For the Interstate Highway in the central United States nicknamed `` double nickel '', see Interstate 55. 55 mph speed limit sign being erected in response to the National Maximum Speed Law. 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. While Federal officials hoped gasoline consumption would fall by 2.2 %, actual savings were estimated at between 0.5 % and 1 %. The law was widely disregarded by motorists, and some states opposed the law, but many jurisdictions discovered it to be a major source of revenue. 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 65 mph ( 105 km / h ) limits on certain limited access, rural roads. Congress repealed the NMSL in 1995, fully returning speed limit setting authority to the states. The law 's safety benefit is disputed as research found conflicting results. Contents 1 History 1.1 1973 -- 55 mph National Speed Limit 1.2 Enactment 1.3 Safety impact 1.4 Fuel savings 1.5 Opposition and noncompliance 1.6 1987 and 1988 -- 65 mph limit 1.6. 1 Reclassified roads 1.7 1995 -- Repeal of federal limits 2 Speedometers 3 In popular culture 4 Annotations 5 References 6 Further reading 7 External links History Historically, the power to set speed limits belonged to the states. Immediately before the National Maximum Speed Law became effective, speed limits were as high as 75 mph ( 120 km / h ). ( Kansas had lowered its turnpike speed limit from 80 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 In 1973, Congress enacted a national speed limit of 55 mph ( 90 km / h ). Some states, such as Washington, enacted lower speed limits. As of November 20, 1973, several states had modified speed limits : 50 mph ( 80 km / h ) : Rhode Island, Maryland, Massachusetts, New Jersey, New York, Vermont, and Washington 55 mph ( 90 km / h ) : North Carolina and Oregon California lowered some 70 mph ( 115 km / h ) limits to 65 mph ( 105 km / h ). In late November 1973, Texas Governor Dolph Briscoe recommended adoption of a 55 mph ( 90 km / h ) statewide limit. On December 4, the Texas Highway Commission, with a 3 -- 0 vote, adopted this 55 mph ( 90 km / h ) speed limit, citing unsafe speed differentials between the flow of traffic and people driving too slowly to comply with President Nixon 's and Governor Briscoe 's requests for voluntary slowdowns. The legality of the measure was questioned, and two Texas legislators threatened to sue to block the limit. However, 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. As an emergency response to the 1973 oil crisis, on November 26, 1973, President Richard Nixon proposed a national 50 mph ( 80 km / h ) speed limit for passenger vehicles and a 55 mph speed limit for trucks and buses. That, combined with a ban on ornamental lighting, no gasoline sales on Sunday, and a 15 % cut in gasoline production, were proposed to reduce total gas consumption by 200,000 barrels a day, representing a 2.2 % drop from annualized 1973 gasoline consumption levels. Nixon partly based this on a belief that cars achieve maximum efficiency between 40 and 50 mph ( 65 and 80 km / h ) and that trucks and buses were most efficient at 55 mph ( 90 km / h ). The California Trucking Association, the then - 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 enacted the National Maximum Speed Law. States had to agree to the limit if they desired to receive federal funding for highway repair. The uniform speed limit was signed into law by President 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 55 mph ( 90 km / h ) 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 Thruway, the 50 mph ( 80 km / h ) speed limit had to be raised to comply with the law. The law capped speed limits at 55 mph ( 90 km / h ) 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 55 mph ( 90 km / h ). 9 states had maximum speed limits of 50 mph ( 80 km / h ). 29 states had lower limits. This 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 Robert Dole to raise the speed limit to 60 mph ( 95 km / h ). Safety impact The limit 's effect on highway safety is unclear. During the time the law was enacted and after it was repealed automobile fatalities decreased, and this was widely attributed mainly to automobile safety improvements, owing to an increase in the safety of cars themselves. This decrease in fatalities from automobile accidents makes figuring out the actual impact of the law difficult. According to the National Research Council, there was a decrease in fatalities of about 4,000 lives in the first year after the law took effect. 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 noted that on rural interstates, the free - flowing traffic speed should be the major determinant of the speed limit, because `` 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 speed laws 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. Insurance Institute for Highway Safety workers wrote three papers that argue that increase from 55 to 65 mph ( 90 to 105 km / h ) on rural roads led to a 25 % to 30 % increase in deaths ( 1 / 3 from increased travel, 2 / 3 from increased speed ) while the full repeal in 1995 led to a further 15 % increase in fatalities. In contrasting work, 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 65 mph ( 105 km / h ) caused a 3.4 % to 5.1 % decrease in fatalities. Fuel savings In 1998, the U.S. Transportation Research Board footnoted an estimate that the 1974 National Maximum Speed Limit ( NMSL ) reduced fuel consumption by 0.2 to 1.0 percent. Rural interstates, the roads most visibly affected by the NMSL, accounted for 9.5 % of the U.S ' vehicle - miles - traveled in 1973, but such free - flowing roads typically provide more fuel - efficient travel than conventional roads. Conservative think tank The Heritage Foundation claims that the United States Department of Transportation 's Office of Driver Research found total fuel savings to be 1 % and that `` independent studies '' found a 0.5 % savings. Opposition and noncompliance 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 through 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 $248 today ) or 30 days jail on a first offense to $500 ( 1982 dollars, equal to $1,241 today ), up to 180 days in jail, and a six - month driver 's license revocation upon third conviction in 18 months. In the 4th quarter of 1988, 85 % of drivers violated the 55 mph ( 90 km / h ) speed limits on Connecticut rural interstates. In 1985, the 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 limit : Arizona, Idaho, Montana, Nevada, and Utah replaced traditional speeding fines with $5 -- $15 energy wasting fines as long as drivers did not exceed the speed limit in effect before the 55 mph federal requirement. Nevada 's energy wasting fine was enacted on April 15, 1981, when signed by Governor Robert List. Motorists not exceeding 70 mph ( 115 km / h ) in 55 mph ( 90 km / h ) zones could be issued $5 `` energy wasting '' fines. However, standard speeding tickets were still allowed and `` troopers were directed not to take the new law as a signal to stop writing tickets ''. In 1986, North Dakota 's fine for speeding up to 15 mph ( 25 km / h ) over the limit was only $15 and had no license points. South Dakota cut speeding fines in 1985 and stopped assessing points for being 10 mph ( 15 km / h ) or less above the speed limit in 1986. On August 1, 1986, Minnesota, which normally suspended licenses after three tickets, stopped counting speeding tickets for no more than 65 mph ( 105 km / h ). In 1981, 33 state legislatures debated measures to oppose the NMSL. Some law enforcement officials openly questioned the speed limit. In 1986, Jerry Baum, director of the South Dakota Highway Patrol, said `` Why must I have a trooper stationed on an interstate, at 10 in the morning, worried about a guy driving 60 mph on a system designed to be traveled at 70 ? He could be out on a Friday night watching for drunken drivers. '' Even organizations supporting the NMSL, such as the American Automobile Association ( AAA ) provided lists of locations where the limit was strictly enforced. On June 1, 1986, Nevada challenged the NMSL by posting a 70 mph ( 115 km / h ) limit on 3 miles ( 5 km ) of Interstate 80. The Nevada statute authorizing this speed limit included language that invalidated itself if the federal government suspended transportation funding. Indeed, the Federal Highway Administration immediately withheld highway funding, which automatically invalidated the statute by its own terms. 1987 and 1988 -- 65 mph limit In the April 2, 1987, Surface Transportation and Uniform Relocation Assistance Act, Congress permitted states to raise speed limits to 65 mph ( 105 km / h ) on rural Interstate highways. In a bill that passed in mid-December 1987, Congress allowed certain non-Interstate rural roads built to Interstate standards to have the higher speed limits. As of December 29, 1987, the states of California, Florida, Illinois, Iowa, Kansas, Kentucky, and Oklahoma had applied for and been accepted into this program. The program was originally slated to last four years. Reclassified roads A few roads that were n't Interstate Highways but were built to Interstate standards were redesignated as Interstate Highways to qualify for the increased speed limit : Kansas petitioned the Federal Highway Administration on May 14, 1987, to `` designate the turnpike as an Interstate Highway between Topeka and Emporia ''. This Kansas Turnpike segment had existed since 1956 without a numerical designation. Interstate status was granted, Interstate 335 was designated, and the 65 mph speed limit signs went up. Interstate 88 in Illinois had previously been designated as Illinois Route 5. 50 miles ( 80 km ) of the Maine Turnpike between Portland and West Gardiner were designated as Interstate 495 in 1988. The designation for this segment was changed in 2004 to Interstate 95 to simplify the Interstate numbering scheme in Maine. 1995 -- repeal of federal limits Congress lifted all federal speed limit controls in the National Highway System Designation Act of 1995, returning all speed limit determination authority to the states effective December 8, 1995. Several states immediately reverted to already existing laws. For example, most Texas rural limits that were above 55 mph ( 90 km / h ) in 1974 immediately reverted to 70 mph ( 115 km / h ), causing some legal confusion before the new signs were posted. Montana reverted to non-numerical speed limits on most rural highways, although its legislature adopted 75 mph ( 120 km / h ) as a limit in 1999. Hawaii was the last state to raise its speed limit when, in response to public outcry after an experiment with traffic enforcement cameras in 2002, it raised the maximum speed limit on parts of Interstates H - 1 and H - 3 to 60 mph ( 95 km / h ). Despite the repeal of federal speed limit controls, 2011 maximum speed limits were, on average, lower than in 1974 : States with same speed limit as pre-1974 : 25 States with higher speed limit than pre-1974 : 8 States with lower speed limits than pre-1974 : 17 The introduction to 70 or 75 mph speed limits was in effect that year. The introduction to 80 mph limits was in about 2005, and Texas introduced 85 ( 140 ) in 2011. Speedometers 55MPH is emphasized on this dashboard. On October 1, 1980, in a regulation that also regulated speedometer and odometer accuracy, the National Highway Traffic Safety Administration ( NHTSA ) required speedometers to have special emphasis on the number 55 and a maximum speed of 85 mph ( 137 km / h ). However, on October 19, 1980, NHTSA proposed eliminating speedometer and odometer rules because they were `` unlikely to yield significant safety benefits '' and `` ( a ) highlighted ' 55 ' on a speedometer scale adds little to the information provided to the driver by a roadside speed limit sign. '' In popular Culture The number 55 became a popular shorthand for the 55 mph speed limit. For example, a hand with a pair of fives in Texas hold'em poker is referred to as a `` speed limit ''. Rock musician Sammy Hagar released `` I Ca n't Drive 55 '', a hit single protesting the rule. The title of Minutemen 's critically acclaimed double album Double Nickels on the Dime refers to the NMSL, and in jest, to the Sammy Hagar single. One of a series of advertising campaigns for the 55 mph speed limit offered, `` Speed limit 55. It 's not just a good idea. It 's the law. '' Intelligentsia riffed that with a more absolute statement based on the speed of light : `` 186,000 miles per second. It 's not just a good idea, it 's the law. '' Annotations Jump up ^ The 2.2 % drop figure was calculated by finding daily consumption to be 9,299,684 barrels of petroleum. Obtain 1973 's petroleum consumption from transportation sector at 2.1 e from the Energy Consumption by Sector section, then convert to barrels using A1 in the Thermal Conversion Factors section ( assume `` conventional motor gasoline '' since ethanol - based or purportedly smog - reducing gas was not common in 1973 ). Jump up ^ Includes Texas where the same pre-1974 speed limits are applicable on the vast majority of rural roads despite some 75 and 80 mph limits. Jump up ^ Includes Virginia where the vast majority of rural freeways have a 65 mph ( 105 km / h ) limit. References Jump up ^ `` Daytime Speed Limits ''. States ' Attitudes Toward Speed Limits. Reasonable Drivers Unanimous. March 9, 1998. Retrieved August 1, 2011. Jump up ^ Lindsey, Robert ( November 20, 1973 ). `` Nation Is Living on Less Energy For Travel, Heating and Lights ''. The New York Times. p. 1. Retrieved July 22, 2008. ( subscription required ) Jump up ^ `` Speed Limit on State Agenda ''. Associated Press. December 3, 1973. Retrieved July 22, 2008. ( subscription required ) Jump up ^ `` Texas Commission OKs 55 MPH Limit ''. Associated Press. December 5, 1973. Retrieved July 22, 2008. ( subscription required ) Jump up ^ Kinch, Jr., Sam ( December 6, 1973 ). `` Lower Speed Limit Not Legal, Hill Rules ''. The Dallas Morning News. p. 1. Retrieved July 22, 2008. ( subscription required ) Jump up ^ Cowan, Edward ( November 27, 1973 ). `` Politics and Energy : Nixon 's Silence on Rationing Reflects Hope That Austerity Can Be Avoided ''. The New York Times. p. 30. Retrieved July 22, 2008. ( subscription required ) Jump up ^ Staff ( June 28, 2008 ). Annual Energy Review ( PDF ) ( 2007 ed. ). Washington, DC : Energy Information Administration. Jump up ^ `` 55 Mile - per - hour Speed Limit Approved by House ''. United Press International. December 4, 1973. p. 30. Retrieved July 22, 2008. ( subscription required ) Jump up ^ `` Unequal Limits Hit ''. United Press International. November 30, 1973. Retrieved July 22, 2008. ( subscription required ) Jump up ^ Travel Mode Improvement Program staff. `` Chapter 8. Transition to Short - Term Planning ''. TMIP : Urban Transportation Planning In the United States : An Historical Overview. US Department of Transportation. Archived from the original on April 8, 2009. Retrieved July 22, 2008. ^ Jump up to : `` Nixon Approves Limit of 55 MPH ''. The New York Times. January 3, 1974. pp. 1, 24. Retrieved July 22, 2008. ( subscription required ) ^ Jump up to : `` Brief For The Respondents In Opposition ''. Nevada v. Skinner. Archived from the original on November 28, 2010. Retrieved August 1, 2011. Jump up ^ Cowan, Edward ( May 14, 1974 ). `` Senate Rejects a Rise in Speed Limits on Highways to 60 MPH from 55 ''. The New York Times. p. 74. Retrieved July 22, 2008. ( subscription required ) Jump up ^ Morrow, Adrian ( April 5, 2011 ). `` US Motorists Enjoy Least Deadly Driving Year Since 1949 ''. Globe and Mail. Toronto. Retrieved August 1, 2011. ^ Jump up to : McFeatters, Ann ( September 14, 1986 ). `` Critics say auto safety laws not worth cost ''. Houston Chronicle. Scripps - Howard News Service. p. 18. Archived from the original on October 18, 2012. Retrieved July 22, 2008. ^ Jump up to : Staff ( May 2011 ). `` Q&A : Speed and speed limits ''. Insurance Institute for Highway Safety. Retrieved August 1, 2011., citing Transportation Research Board. 1984. 55 : a decade of experience. Special Report 204. Washington, DC., available for purchase online at ( 1 ) Jump up ^ `` Road Conditions Vary Too Widely For Single Approach to Speed Limits ''. Transportation Research Board. National Research Council. Oct 1, 1998. Retrieved November 3, 2011. Jump up ^ Moore, Stephen ( May 31, 1999 ). `` Speed Does n't Kill : The Repeal of the 55 - MPH Speed Limit ''. Cato Institute. pp. 7 -- 9. Retrieved April 19, 2007. Jump up ^ Lave, Charles ; Elias, Patrick. `` Did the 65 MPH Speed Limit Save Lives ? '' ( PDF ). Accident Analysis and Prevention. Amsterdam : Elsevier. 26 ( 1 ) : 49 -- 62. ISSN 0001 - 4575. doi : 10.1016 / 0001 - 4575 ( 94 ) 90068 - x. Jump up ^ `` Special Report 254 : Managing Speed '' ( PDF ). Transportation Research Board : 189. Retrieved 17 September 2014. Bloomquist ( 1984 ) estimated that the 1974 National Maximum Speed Limit ( NMSL ) reduced fuel consumption by 0.2 to 1.0 percent. Jump up ^ `` Highway Statistics 1973 ( Table VM - 2 : VEHICLE MILES, BY STATE AND HIGHWAY SYSTEM - 1973 ) '' ( PDF ). Federal Highway Administration : 76. Retrieved 17 September 2014. Jump up ^ Lexus IS250 2.5 L 6cyl, Auto 6 speed Sedan, 5 seats, 2WD Jump up ^ 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 http://www.lexus.de/range/is/index.aspx Jump up ^ 2009 Lexus IS 250 6 cyl, 2.5 L, Automatic ( S6 ), Premium http://www.fueleconomy.gov/feg/findacar.htm Jump up ^ Copulos, Milton R. ( September 9, 1986 ). `` The High Cost of the 55 MPH Speed Limit '' ( PDF ). The Backgrounder. Washington, DC : The Heritage Foundation ( 532 ) : 1 -- 8. Retrieved August 1, 2011. ^ Jump up to : Grimes, Paul ( December 26, 1982 ). `` Practical Traveler : The 55 - MPH Speed Limit ''. The New York Times. Retrieved August 1, 2011. Jump up ^ Hamilton, Robert A. ( May 7, 1989 ). `` 85 % of Drivers on Interstates Are Speeders ''. The New York Times. Retrieved August 1, 2011. Jump up ^ `` Speeders in Majority on Texas Highways ''. Houston Chronicle. United Press International. January 9, 1987. p. 12. Retrieved August 1, 2011. Jump up ^ Robison, Clay ( June 15, 1986 ). `` 55 MPH Law Violated, but Unlikely to Change ''. Houston Chronicle. p. 2. Retrieved August 1, 2011. Jump up ^ `` Nevada Speeders Getting $5 ' Energy Wasting ' Fines ''. The New York Times. Associated Press. April 16, 1981. Retrieved August 1, 2011. ^ Jump up to : `` Some States Trying to Skirt Federally Mandated 55 MPH Speed Limit ''. Houston Chronicle. April 14, 1986. p. 3. Retrieved August 1, 2011. Jump up ^ Molotsky, Irvin ( December 29, 1987 ). `` 20 States to Win the Right to Set a 65 MPH Speed ''. The New York Times. Retrieved August 1, 2011. Jump up ^ `` 65 MPH Approved for Route ''. Wichita Eagle - Beacon. October 24, 1987... Jump up ^ `` It 's Time To Clear Up the Confusion : Maine Interstate Redesignation 2004 '' ( PDF ). Maine Department of Transportation and Maine Turnpike Authority. 2004. Retrieved August 1, 2011. Jump up ^ Antone, Rod ( April 18, 2002 ). `` State Approves Higher Speed Limits ''. Honolulu Star - Bulletin. Retrieved August 1, 2011. Jump up ^ Staff. `` Summary Chart ''. States ' Attitudes Towards Speed Limits. Reasonable Drivers Unanimous. Retrieved August 1, 2011. Jump up ^ Kramer, Larry ( March 10, 1978 ). `` Odometer Security Rules Due ''. Washington Post. p. B11. Retrieved July 22, 2008. ( subscription required ) Jump up ^ National Highway Traffic Safety Administration ( effective September 1, 1979 ). 49 C.F.R. 571.127 `` Standard No. 127 Speedometers and Odometers. '' Retrieved August 1, 2011. Jump up ^ Conlon, Michael J. ( October 22, 1981 ). `` Speedometer Rules Slated for Scrapping ''. United Press International. Retrieved July 22, 2008. ( subscription required ) Jump up ^ McComas, Richard ( 2004 - 12 - 05 ). `` 400 + Hole Card Hand Names ''. Retrieved 2008 - 10 - 11. Jump up ^ Bennett, James T. ( 2014 ). Mandate Madness : How Congress Forces States and Localities to Do Its Bidding. New Brunswick, New Jersey : Transaction Publishers. ISBN 978 - 1 - 4128 - 5372 - 9. Jump up ^ Van Riper, A. Bowdoin ( 2002 ). Science in Popular Culture : A Reference Guide. Westport, Connecticut, USA : Greenwood Press. p. 268. ISBN 0 - 313 - 31822 - 0. Further reading Singell, Larry D. ; McNown, Robert F. ( October 1985 ). `` A Cost - Benefit Analysis of the 55 MPH Speed Limit : Reply ''. Southern Economic Journal. Chapel Hill, NC : Southern Economic Association, University of North Carolina at Chapel Hill. 52 ( 2 ) : 550 -- 553. ISSN 0038 - 4038. JSTOR 1059644. doi : 10.2307 / 1059644. Clotfelter, Charles T. ; Hahn, John C. ( June 1978 ). `` Assessing the 55 MPH National Speed Limit ''. Policy Sciences. Springer Netherlands. 9 ( 3 ) : 281 -- 294. ISSN 0032 - 2687. doi : 10.1007 / BF00136831. External links External images `` Photograph of 55 mph speed limit replacing a 70 mph limit ''. February 12, 1974. `` Photograph of KSDOT workers changing a 75 mph sign to 55 mph ''. 1974. 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'' sign Old age and driving Sleep deprived driving Slow moving vehicle Vision Zero Retrieved from `` https://en.wikipedia.org/w/index.php?title=National_Maximum_Speed_Law&oldid=807963691 '' Categories : Road transport United States federal transportation legislation United States repealed legislation Traffic law Hidden categories : Pages containing links to subscription - only content Use mdy dates from April 2012 All articles with unsourced statements Articles with unsourced statements from September 2011 Talk Contents About Wikipedia Eesti Edit links This page was last edited on 31 October 2017, at 02 : 12. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: when did the speed limit change to 55 mph
Answer: 1974