Speed limits in the United States

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US Speed Limits May 2015.svg

Speed limits in the United States are set by each state or territory. Speed limits are typically posted in increments of five miles per hour (mph). Some states have lower limits for trucks and at night, and occasionally there are minimum speed limits. Most speed limits are set by state or local statute, although each state allows various subdivisions to set a different, generally lower, limit.

The highest speed limits are generally 75–80 mph (120–130 km/h) in western states and 70 mph (115 km/h) in eastern states. A few states, mainly in the Northeast Megalopolis, have 65 mph (105 km/h) limits, and Hawaii has a maximum limit of 60 mph (95 km/h). Portions of the Idaho, Montana, Nevada, South Dakota, Texas, Utah, and Wyoming road networks have 80 mph (130 km/h) limits. For 13 years (1974–1987), federal law prohibited[not verified in body] speed limits above 55 mph (90 km/h). From 1987 through December 8, 1995, an amended federal law prohibited speed limits above 65 mph (105 km/h).

A standard sign indicating a speed limit of 80 miles per hour (mph), a night-time speed limit of 65 mph, and a truck speed limit of 55 mph
A speed limit sign entering a school zone, along with a warning light above
Variety used in Oregon, omitting the word LIMIT. The typeface of the numerals varies significantly due to its non-standard design. See Oregon speed limits.


Speed limits[edit]

This table contains the most usual daytime speed limits, in miles per hour, on typical roads in each category. The values shown are not necessarily the fastest or slowest. They usually indicate, but not always, statutory speed limits. Some states and territories have lower truck speed limits applicable to heavy trucks. If present, they are usually only on freeways or other high speed roadways.

State or territory Freeway (rural) Freeway (trucks) Freeway (urban) Divided (rural) Undivided (rural) Residential
Alabama Alabama[1] 70 60 65 35–55 15–25
Alaska Alaska 65 60 55 55–65 20–25
American Samoa American Samoa[2] 25–30 15
Arizona Arizona[3] 75 55-65 65 65 15–25
Arkansas Arkansas 70 65 65 55–60 30
California California 65–70 55 55–65 60–65 50–65 25–30
Colorado Colorado 65–75 55–65 65 35–65 20–35
Connecticut Connecticut 65 45–55 55 45–55 20–40
Delaware Delaware[4] 65 50–65 55 50 20–35
Washington, D.C. District of Columbia[5] 50–55 15–25
Florida Florida[6] 70 55–65 65 55–60 10–30
Georgia (U.S. state) Georgia[7] 70 55–70 65 55 25–45
Guam Guam[8] 35–45 35–45
Hawaii Hawaii 55–60 50 45 45-55 25
Idaho Idaho 75–80 70 65 70 55–70 25–30
Illinois Illinois 70 45–70 65 55 20–30
Indiana Indiana 70 65 55–65 55-60 50-55 20–30
Iowa Iowa 70 55–65 65 45–55 25
Kansas Kansas 75 65 65–70 55–65 20–30
Kentucky Kentucky[9] 70 55–70 55–65 55 25–45
Louisiana Louisiana 70–75 60 65 45–55 10–45
Maine Maine 70–75 55–60 55–60 50–55
Maryland Maryland 65–70 55–65 55 50–55 15–25
Massachusetts Massachusetts 65 55–65 55 55 20–30
Michigan Michigan[10] 70 60 55–70 55–65 55 25
Minnesota Minnesota[11][12] 70 45–65 65 55–60 30
Mississippi Mississippi 70 60–70 65 55 25
Missouri Missouri 70 60–65 65–70 55–65 35–40
State or territory Freeway (rural) Freeway (trucks) Freeway (urban) Divided (rural) Undivided (rural) Residential
Montana Montana 75–80 65 65 65–70 55–70 15–25
Nebraska Nebraska[13] 75 60 65 50–65 25
Nevada Nevada 70–80 60–65 55–75 55–70 15–30
New Hampshire New Hampshire 65–70 55 55 35–55 20–30
New Jersey New Jersey[14][15] 65 55–65 55 30–55 15–35
New Mexico New Mexico[16] 75 55–75 65–75 25–65 (55 default limit effective 2016-01-01) 15–55
New York New York 65 35–65 55 55 15–45
North Carolina North Carolina[17][18][19] 65–70 55–65 55–60 55 20–35
North Dakota North Dakota[20][21] 75 55–75 70 40–70 5–75
Ohio Ohio[22] 70 55–65 60–70 55 20–35
Oklahoma Oklahoma 70 (75 turnpikes) 55–65 60–70 45–65 25
Oregon Oregon 65 (65–70 effective: 2016-03-01) 55 (65 effective 2016-03-01) 50–60 55 (55–70 effective 2016-03-01) 55 (55–70 effective 2016-03-01) 20–25
Pennsylvania Pennsylvania 65–70 50–65 55 40–55 15–35
Puerto Rico Puerto Rico[23] 60–65 50–55 50–55 45–55 45–55 15–35
Rhode Island Rhode Island[24] 65 55 55 50 20–25
South Carolina South Carolina[25] 70 60 60 55 30
South Dakota South Dakota[26][27] 75–80 55–80 65–70 35–65 15–45
Tennessee Tennessee 70 55–70 65 35–55 30
Texas Texas 75–85 55–75 70–75 30–75 15–55
United States Virgin Islands U.S. Virgin Islands[28] 55 35 20
Utah Utah[29][30] 80 65-70 65 65 20–35
Vermont Vermont 65 55 55 50–55
Virginia Virginia[31] 65–70 55–65 55–60 55 15–35
Washington (state) Washington 70 60 60 60–70 55–65 20–50
West Virginia West Virginia 70 60–65 65 55 15–55
Wisconsin Wisconsin[32] 70 55–70 65 55 15–35
Wyoming Wyoming[33] 75–80 65 70 70 30

Examples of related laws[edit]

State Typical fine Recklessness threshold or enhanced penalty Absolute/prima facie Ticket dismissal options Point system
 North Carolina $10–$50 plus court costs.[34] Speeding fines in work zones and school zones are $250 plus court costs. >15 mph over limit (at a travelled speed of greater than 55 mph) or over 80 mph Absolute Prayer for judgment continued (PJC) available depending on the court and subject to their discretion, but not available for charges of exceeding a speed limit by more than 25 mph. Point system may lead to license suspension. Exceeding the speed limit by more than 15 mph with a speed of greater than 55 mph or travelling faster than 80 mph results in a minimum 30-day license suspension.[35]
 Pennsylvania $35[36] plus court and other costs. All fines doubled in active work zones. >30 mph over limit Absolute None Point system leads to mandatory driver education and possible license suspension.
 Texas $1–$200[37] plus court fees. Doubled in active school zone or construction zone when workers are present.[38] Various additional "fees" assessed by the state essentially increase the fine by around $100 on all tickets. None[39] Prima facie[40] Defensive driving[41] (once per year) or deferred disposition[42] (restrictions vary, but generally at least 4 per year), but only valid if:
  • Texas resident,
  • Speed < 25 mph above limit and < 95 mph, and
  • Not in construction zone where workers are present or active school zone.
  • Not a Commercial Driver License (CDL) holder.
Point system is annual surcharge only. No provision for license suspension if surcharges are paid.[43]
 Rhode Island Prima facie One dismissal every 3 years for speed 14 mph or less over limit.[44]
  • Up to $250[45]
  • School zone: up to $250 additional[46]
  • Work zone: up to $500[47]
  • $200 civil penalty in certain towns[48]
20 mph over limit or over 80 mph[49] or.[50] Absolute[51] Point system[52] leading to fines, suspension, and mandatory driver education.[53]


The first speed limit in the United States was set in Boston in 1757 by the board of selectmen (similar to a city council). The speed limit for wagons, carriages, horses, etc. on Sunday was set at a walking pace. Anyone exceeding this limit would be fined 10 shillings (equal to £59.89 today).[54]

Federal speed controls[edit]

A sign next to a highway says "Speed Limit 50". A newspaper in the foreground has an article about the new speed limit.
In 1973, Congress enacted a national speed limit of 55 mph (89 km/h). Some states, such as Washington, enacted lower speed limits.
For more details on this topic, see National Maximum Speed Law.

In response to the 1973 oil crisis, Congress enacted the National Maximum Speed Law that created the universal 55 miles per hour (89 km/h) speed limit.[citation needed] Whether this reduced gasoline consumption is debated and the impact on safety is unclear; studies and opinions of safety advocates are mixed.

The law was widely disregarded by motorists, even after the national maximum was increased to 65 miles per hour (105 km/h) on certain roads in 1987 and 1988. In 1995, the law was repealed, returning the choice of speed limit to each state.

Minimum speed limits[edit]

Speed limit 70 minimum 40 sign.svg

In addition to the legally defined maximum speed, minimum speed limits may be applicable. Occasionally, there are default minimum speed limits for certain types of roads, generally freeways.

Comparable to the common basic speed rule, most jurisdictions also have laws prohibiting speeds so low they are dangerous or impede the normal and reasonable flow of traffic.

Truck speed limits[edit]

Trucks speed 55 sign.svg

Some jurisdictions set lower speed limits that are applicable only to large commercial vehicles like heavy trucks and buses. While they are called "truck speed limits", they generally do not apply to light trucks.


The research record is mixed. A 1987 study finds that crash involvement significantly increases when trucks drive much slower than passenger vehicles,[55] suggesting that the difference in speed between passenger vehicles and slower trucks could cause crashes that otherwise may not happen. Furthermore, in a review of available research, the Transportation Research Board (part of the United States National Research Council) states "[no] conclusive evidence could be found to support or reject the use of differential speed limits for passenger cars and heavy trucks" (page 11) and "a strong case cannot be made on empirical grounds in support of or in opposition to differential speed limits" (page 109).[56]

One study has claimed that two thirds (67%) of truck/passenger car crashes are the fault of the passenger vehicle.[57]

Night speed limits[edit]

Night speed limit in the Key Deer habitat on the Florida Keys. Note the nonreflective backing of the day speed limit number. At night, only the number on the lower sign is visible in the headlights.

The basic speed rule requires drivers adjust speeds to the conditions. This is usually relied upon to regulate proper night speed reductions, if required. Numeric night speed limits, which generally begin 30 minutes after sunset and end 30 minutes before sunrise, are occasionally used where, in theory, safety problems require a speed lower than what is self-selected by drivers.

Examples include:

  • Some streets in Tucson, Arizona without street lights.
  • Some Florida roads near SW Florida Int'l Airport near Cape Coral/Fort Myers. (Most of these roads are labeled as "Panther Zones" or "Panther X-ing" areas.)
  • Daniels Parkway Ext., a 4 lane divided Hwy near SW Fl Int't Airport with 50 mph daytime limit, and a night speed limit of 45 mph is considered by many to be a speed trap[citation needed]. This road joins neighboring SR 82, a 2 lane road with a 60 mph speed limit.
  • Colorado Highway 13, with a 65 mph day/55 mph night speed limit beginning 7.1 mi. north of I-70 from north of Rifle to CO. Hwy. 64 south of Meeker. Rural Colorado Hwy. 13 is 55 mph at night north of Meeker all the way to the Wyoming state line.

Some states create arbitrary night speed limits applicable to entire classes of roads. Until September 2011, Texas had a statutory 65 mph night speed limit for all roads with a higher limit. Montana has a statutory 65 mph night speed limit on all federal, state, and secondary roads except for Interstates.

Political considerations[edit]


70 mph limit on Texas Farm to Market Road 50 immediately south of Texas State Highway 21

Subjective or political influence on speed limits is evident by state-to-state speed limit variances that have no empirical justification. Highlighted examples include:

  • All 51 miles (82 km) of I-95 in Pennsylvania are posted at 55 mph, while in neighboring New Jersey, the speed limit on I-95 is primarily 65 mph, despite their common suburban environment.
  • Cars and trucks traveling on US Route 30 from Indiana to Ohio can increase their speeds from 60 mph to 70 mph while cars and trucks traveling on the same roadway westbound from Ohio into Indiana will need to drop their speeds from 70 mph to 60 mph despite similar scenery and road configurations.
  • Ohio has no separate truck speed limit on its interstates, but Michigan on the other hand has a 10 mph reduction for trucks. (If the speed limit for cars is 70, then the truck speed limit is 60). Interstate 75 in Ohio just south of the Michigan state line has a uniform 65 mph limit. Thus, cars traveling north on I-75 into Michigan are allowed to speed up by 5 mph, but trucks actually have to do the exact opposite and slow down by 5 mph on the same roadway.
  • The lowest class of state-maintained, two-lane road in Texas may have a 75 mph speed limit, but a two-lane US highway built to neighboring Arkansas's or Louisiana's highest standards may not have a speed limit over 55.
  • Several roads in Minnesota and Missouri such as U.S. Routes 75, 59, and 71 have 60 mph limits while Iowa has only 55 mph limits for the same roads.
  • Trucks traveling westbound on I-10 or I-40 from Arizona (which has no separate truck speed limit) into California see their legal speed limit drop from 75 mph to 55 mph, despite similar road conditions.
  • Only 6 states allow two-lane highways to be posted at 70 mph or higher: Idaho, Montana, Nevada, Oregon (when new signs are installed which is expected to be in early March 2016 on US Route 95), Texas and Wyoming (as of 9/1/2015, no non interstate highway in Wyoming has a speed limit greater than 65 mph.) *(Texas as of 2015 allows 70- 75 meh limits on some two lanes, mainly rural roads)

Even in-state examples point to arbitrariness. For example, I-10 and I-20 in far west Texas have had the following speed limits despite no significant changes in roadway characteristics:

  • Before 1963: 60 mph day/55 mph night
  • 1963–1974: 70 mph day/65 mph night
  • 1974–1986: 55 mph (National Maximum Speed Law)
  • 1986–1995: 65 mph (NMSL 65 mph amendment)
  • 1995–2001: 70 mph day/65 mph night
  • 2001–2006: 75 mph day/65 mph night
  • 2006–2012: 80 mph day/65 mph night
  • 2012–: 80 mph

Financial concerns[edit]

Traffic violations can be a lucrative income source for jurisdictions and insurance companies. For example:

  • Westlake, TX took in $42,000 per citizen over nine years for its speed traps.[58]
  • Insurance companies may receive several billions of dollars annually in traffic ticket surcharges.[59]
  • A study by the Federal Reserve of St. Louis found that traffic ticket writing increases when government revenue decreases.[60]
  • 2008 debates over traffic enforcement in Dallas County, TX involved concerns of lost profits if ticketwriting decreased.[61][62][63]
  • In Massachusetts, half of the ticket money goes to the police department that writes the speeding ticket, the other half goes to fund the court that convicts the speeder or collects the fine from them.

Thus, an authority that sets and enforces speed limits, such as a state government, regulates and taxes insurance companies, who also gain revenue from speeding enforcement. Furthermore, such an authority often requires "all" drivers to have policies with those same companies, solidifying the association between the state and auto insurers. If a driver cannot be covered under an insurance policy because of high risk, the state will assume that high risk for a greater monetary amount; thus resulting in even more revenue generation for the state.[64]

When a speed limit is used to generate revenue but has no safety justification, it is called a speed trap. The town of New Rome, Ohio was such a speed trap, where speeding tickets raised up to $400,000 per year to fund the police department of a 12-acre village with 60 residents.[65]

Environmental concerns[edit]

Reduced speed limits are sometimes enacted for air quality reasons. The most prominent example includes Texas' environmental speed limits.

Metric speed limits[edit]

The values of metric speed limits in the US are to be circumscribed in accordance with the MUTCD.

Though not common in the United States, a speed limit may be defined in kilometers per hour (km/h) as well as miles per hour (mph). The Federal Highway Administration's Manual on Uniform Traffic Control Devices, which provides guidelines for speed limit signage, states that "speed limits shown shall be in multiples of 10 km/h or 5 mph."[66] If a speed limit sign indicates km/h, the number is circumscribed and "km/h" is written below. Prior to 2003, metric speed limits were designated using the standard speed limit sign, usually with yellow supplemental "METRIC" and "km/h" plaques above it and below it, respectively.[67][68]

In 1995, the National Highway System Designation Act prohibited use of federal funds to finance new metric signage.

Definition of speeding[edit]

Either of the following qualifies a crash as speed-related in accordance with U.S. government rules:[69]

  1. Exceeding speed limits.
  2. Driving too fast for conditions.

Speeds in excess of speed limits account for most speed-related traffic citations; generally, "driving too fast for conditions" tickets are issued only after an incident where the ticket issuer found tangible evidence of unreasonable speed, such as a crash.

A criticism of the "exceeding speed limits" definition of speeding is twofold:

  1. When speed limits are arbitrary, such as when set through political rather than empirical processes, the speed limit's relationship to the maximum safe speed is weakened or intentionally eliminated. Therefore, a crash can be counted as speed-related even if it occurs at a safe speed, simply because the speed was in excess of a politically determined limit.
  2. The effective limit may still be too fast for certain conditions, such as limited visibility or reduced road traction[70] or even low-speed truck rollovers on exit ramps.[71]

Variable speed limits offer some potential to reduce speed-related crashes. However, due to the high cost of implementation, they exist primarily on freeways. Furthermore, most speed-related crashes occur on local and collector roads, which generally have far lower speed limits and prevailing speeds than freeways.[72]

Prima facie[edit]

Most states have absolute speed limits, meaning that a speed in excess of the limit is illegal per se. However, some states have prima facie speed limits.[73] This allows motorists to defend against a speeding charge if it can be proven that the speed was in fact reasonable and prudent.

Speed limits in Texas,[74] Utah,[75] and Rhode Island are prima facie. Some other states have a hybrid system: speed limits may be prima facie up to a certain speed or only on certain roads. For example, speed limits in California up to 55 mph, or 65 mph on highways, are prima facie, and those at or above those speeds are absolute.[76]

A successful prima facie defense is rare. Not only does the burden of proof rest upon the accused, a successful defense may involve expenses well in excess of the cost of a ticket, such as an expert witness. Furthermore, because prima facie defenses must be presented in a court, such a defense is difficult for out-of-town motorists.

See also[edit]



  1. ^ Alabama Department of Public Safety rem New link for Alabama DPS Speed Limits http://www.dps.alabama.gov/Home/wfContentTableColumned.aspx?ID=40&PLH1=HPSPEEDLIMITS
  2. ^ American Samoa Code Section 22.0323 [1], and Frommer's [2]
  3. ^ Arizona Statutes Chapter 3 Article 6 State Legislature
  4. ^ "Subchapter VIII. Speed Restrictions.". Delaware State Legislature. May 19, 2008. 
  5. ^ District of Columbia Municipal Regulations Title 18 – Vehicle and Traffic (March 1997), chapter 22 "Moving Violations" [3] [4]
  6. ^ http://www.dot.state.fl.us/trafficoperations/FAQs/SpeedLimitFAQ.shtm
  7. ^ "HB 674 – Maximus Speed Limots; vehicles having greater than 6 wheels.". Georgia House of Representatives. May 21, 2008. 
  8. ^ Guam Code Annotated Title 16 Chapter 3 Article 3 § 3301.[5], [6] and [7]
  9. ^ "SENATE TRANSPORTATION COMMITTEE APPROVES SPEED LIMIT INCREASE". Kentucky Transportation Cabinet. February 1, 2006. 
  10. ^ "Public Michigan Vehicle code: Speed Restrictions". Michigan Legislature. November 9, 2006. Retrieved April 30, 2007. 
  11. ^ 169.14, Minnesota Statute. Revisor.leg.state.mn.us (August 1, 2009).
  12. ^ HEAT Speed Management Program. Dot.state.mn.us.
  13. ^ http://www.nebraskatransportation.org/docs/speed-limit.pdf
  14. ^ "Chapter 4 Safe Driving Rules & Regulations, (N.J.S.A. 39:4–98).". New Jersey Motor Vehicle Commission. April 24, 2008. 
  15. ^ "Appendix A Designated 65mph Roadway Segments." (PDF). State of New Jersey & New Jersey Department of Transportation. April 24, 2008. 
  16. ^ [New Mexico Statutes Chapter 66 Article 7 part 4 Mexico State Legislature or nmlaws.org
  17. ^ "North Carolina General Statutes § 20-141(d)(2). Speed restrictions." (PDF). North Carolina State Legislature. April 23, 2008. 
  18. ^ "NCDOT, Strategic Highway Corridors, Facility Types and Control Of Access Definitions.". North Carolina Department Of Transportation. April 23, 2008. 
  19. ^ "North Carolina General Statutes § 20-141. Speed restrictions.". North Carolina State Legislature. April 23, 2008. 
  20. ^ http://www.legis.nd.gov/cencode/t39c09.pdf
  21. ^ North Dakota Speed Zone Map
  22. ^ http://onlinedocs.andersonpublishing.com/oh/lpExt.dll?f=templates&fn=main-h.htm&cp=PORC
  23. ^ § 5122. Maximum lawful speed limits and penalties., Subchapter IV, Chapter 27, Title 9 of the Laws of Puerto Rico [8]
  24. ^ "Rhode Island Division Of Motor Vehicles: General Information". State Of Rhode Island, Division Of Motor Vehicles. May 27, 2008. 
  25. ^ "S.C. Code Of Laws Title 56 Chapter 5 Uniform Act Regulating Traffic On Highways.". South Carolina State Legislature. May 1, 2008. 
  26. ^ "Maximum posted speed limits". Insurance Institute for Highway Safety. Retrieved July 2, 2009. 
  27. ^ "What are the speed limits in South Dakota?". South Dakota Highway Patrol. Retrieved July 2, 2009. 
  28. ^ Section 494. speed limits, Chapter 43, Part II, Title 20 of the Virgin Islands Code [9], and from a NHTSA summary [10]
  29. ^ Troopers plan to strictly enforce new 80 mph speed limit. ksl.com (January 5, 2009).
  30. ^ Utah Code 41-6a-601 - Speed regulations. le.utah.gov.
  31. ^ Va. Code § 46.2-870. Leg1.state.va.us.
  32. ^ Wisconsin Statute 346.57. (PDF).
  33. ^ Wyoming Statutes. Legisweb.state.wy.us.
  34. ^ http://www.nccourts.org/Courts/Trial/Documents/01_traffic-waiv2013.pdf
  35. ^ [11]
  36. ^ http://www.dmv.state.pa.us/pdotforms/vehicle_code/chapter33.pdf
  37. ^ TRANSPORTATION CODE CHAPTER 542. GENERAL PROVISIONS. Statutes.legis.state.tx.us.
  38. ^ TRANSPORTATION CODE CHAPTER 542. GENERAL PROVISIONS. Statutes.legis.state.tx.us.
  44. ^ Revised Statutes – Browse Document
  45. ^ Va. Code § 18.2–11. Leg1.state.va.us.
  46. ^ Va. Code § 46.2-873. Leg1.state.va.us.
  47. ^ Va. Code § 46.2–878.1. Leg1.state.va.us (July 1, 2012).
  48. ^ Va. Code § 46.2–874.1. Leg1.state.va.us.
  49. ^ Va. Code § 46.2-862. Leg1.state.va.us.
  50. ^ Va. Code § 46.2-861. Leg1.state.va.us.
  51. ^ Va. Code § 46.2-878. Leg1.state.va.us.
  52. ^ Va. Code § 46.2-492. Leg1.state.va.us.
  53. ^ Commonwealth of Virginia, Department of Motor Vehicles, "Moving Violations and Point Assessments". Dmv.virginia.gov (May 14, 2007).
  54. ^ "First Speed Law in America" Popular Mechanics, December 1930. Books.google.com.
  55. ^ table V-4. (PDF).
  56. ^ Managing Speed: Review of Current Practices for Setting and Enforcing Speed Limits. Trb.org.
  57. ^ The Unsafe Driving Acts of Motorists in the Vicinity of Large Trucks. (PDF).
  58. ^ Small North Texas town tops list in speeding-ticket revenue | wfaa.com Dallas – Fort Worth. Wfaa.com (March 23, 2010).
  59. ^ Traffic Tickets Are Big Business. Blog.motorists.org (November 16, 2010).
  60. ^ St. Louis Fed: WP 2006-048C "Red Ink in the Rearview Mirror: Local Fiscal Conditions and the Issuance of Traffic Tickets". Research.stlouisfed.org.
  61. ^ Dallas County commissioners propose deal to eliminate traffic units, Dallas Morning News, June 27, 2008
  62. ^ As motorists’ frustration rises, justices of the peace pull out of automated ticket payment program, Dallas Morning News, July 5, 2008
  63. ^ Dallas County to scrap central collections for traffic tickets, Dallas Morning News, July 7, 2008
  64. ^ Stephen Moore on Speed Limits on National Review Online. Nationalreview.com (June 25, 2003).
  65. ^ Matt Hannafin (April 11, 2008). Highway Robbery: Coping with the Great American Speed Trap. Frommer's (John Wiley & Sons, Inc.). Retrieved September 8, 2012. 
  66. ^ FHWA – MUTCD – 2003 Edition Revision 1 Chapter 2B. Mutcd.fhwa.dot.gov.
  67. ^ MUTCD and metric road signs in the US. Lamar.colostate.edu.
  68. ^ New York Roads – I-87 – Northway. Alpsroads.net.
  69. ^ U.S. federal government brochure[dead link]
  70. ^ Synthesis of Safety Research Related to Speed, Publication No. FHWA-RD-98-154[dead link]
  71. ^ Vehicular Stability Systems (VSS) – Federal Motor Carrier Safety Administration. Fmcsa.dot.gov.
  72. ^ [12][dead link]
  73. ^ State Traffic and Speed Laws. Mit.edu.
  74. ^ Texas Transportation Code §545.351 and §545.352. Texas Legislature.
  75. ^ Utah State Legislature. Le.utah.gov.
  76. ^ [13]

Law Review[edit]

  • R. A. Vinluan (2008). "Indefiniteness of automobile speed regulations as affecting validity". American Law Reports--Annotated, 3rd Series 6. The Lawyers Co-operative Publishing Company; Bancroft-Whitney; West Group Annotation Company. p. 1326. 
  • C. C. Marvel (2010). "Meaning of "residence district," "business district," "school area," and the like, in statutes and ordinances regulating speed of motor vehicles". American Law Reports--Annotated, 2nd Series 50. The Lawyers Co-operative Publishing Company; Bancroft-Whitney; West Group Annotation Company. p. 343.