Automated Speed Camera Enforcement

A speed camera is a form of automated enforcement of traffic safety laws. Speed cameras photograph a vehicle’s license plate if the driver is speeding, and the vehicle owner or driver is sent a ticket.1 Mobile speed cameras are often used to cover multiple road segments, unlike red light cameras, which are used only at intersections. Automated speed camera enforcement should be used to aid traditional enforcement efforts or in locations where traffic stops are impractical or unsafe.1

Effectiveness and Use of Automated Speed Camera Enforcement

The relationship between driving speed and the risk of a crash and/or fatality is well established.1,2 In 2019, 26% of all motor vehicle fatalities occurred in crashes in which at least one driver was speeding.3 In the same year, results from National Highway Traffic Safety Administration’s Crash Report Sampling System, a sample of police-reported crashes, found speeding was involved in 12% of crashes resulting in injuries/fatalities and 9% of property-damage-only crashes.2

Increased travel speeds as a result of increasing speed limits have a detrimental impact on fatality rates.2 One study analyzed 1982–1989 Fatality Analysis Reporting System (FARS) data to estimate the impact of the speed limit being raised from 55 to 65 mph on rural interstates in many states during 1987–1988. This study found an increase in the fatality risk corresponding to approximately one rural interstate fatality per day in 1989 being attributable to the increased speed limit.4 Another study analyzed FARS data and estimated that 33,000 traffic fatalities would have been prevented if maximum speed limits had stayed the same from 1995–2013 instead of increasing.5

Automated speed camera enforcement is effective in reducing speed and speed-related crashes. In a Cochrane review of studies through 2010 evaluating speed cameras, all studies measuring speed or speeding saw reductions when the cameras were present.6 All studies in the Cochrane review measuring crashes also showed reductions when the cameras were present.6 More recent research has also found reductions in speeding or injury crashes when cameras were present.7,8 For example, a 2016 study reported on the results of a comprehensive evaluation of an automated speed camera enforcement program in Montgomery County, Maryland.8 The evaluation was conducted seven and a half years after the introduction of the speed cameras to residential streets and school zones. Relative to comparable sites without cameras, sites with cameras saw a decrease in mean speeds, a decrease in the likelihood that a driver was driving at more than ten miles per hour above the speed limit, and a reduction in the likelihood of a crash resulting in an incapacitating or fatal injury.8 In a phone survey of drivers in the community, 95% were aware of the speed cameras, and 76% of those aware had reduced their speeds because of the cameras.8

Recent or Current Legislation by State

You can visit the automated enforcement laws by stateexternal icon web page on the Insurance Institute for Highway Safety’s website for up-to-date information on automated speed camera enforcement by state.9

Costs of Automated Speed Camera Enforcement and Time to Implement

Camera equipment may be purchased, leased, or operated by a vendor.1 Most jurisdictions work with vendors to install cameras, process images, and issue citations.1 Costs of implementation depend on equipment type, program characteristics, and vendor negotiations. Vendor payments are made either on a set monthly basis or based on the number of citations.1 Several studies have found net cost benefits to society for the use of speed cameras.1

It generally requires up to nine months for full automated speed camera enforcement implementation after any relevant legislation has been enacted.1

Other Issues and Resources

In a report for the Governors Highway Safety Association, equitably implemented and transparent automated enforcement was recommended as a strategy to advance racial equity in traffic enforcement.10

You can read Chapter 3, Section 2.1 of NHTSA’s Countermeasures that Work: A Highway Safety Countermeasure Guide for State Highway Safety Officespdf iconexternal icon (Tenth Edition, 2020) to learn more about the topics above or other issues related to speed camera enforcement, such as variation in state laws, differential public acceptance (e.g., higher support of use around school zones), positive or negative spillover effects, average speed over distance enforcement, and enforcement thresholds.1

You can read the RAND Corporation’s final reports for MV PICCS 1.0/2.0external icon and MV PICCS 3.0external icon for more information about how effectiveness and costs were incorporated into the MV PICCS tool for this intervention.


Each state is responsible for setting its own maximum speed limit laws.2 In 1901, Connecticut was the first state to pass a law regulating the speed of motor vehicles.11 In 1973, a national maximum speed limit of 55 mph was established using restrictions on federal funding for states.2 However, speed limits have increased since the relaxation of the law in 1987 to allow for speed limits of up to 65 mph on rural interstates and the repeal of the law in 1995.2

The first speed cameras in the United States were installed in 1987 in the Peoria and Paradise Valley communities in Arizona.2 As of January 2022, 171 communities in 18 states and the District of Columbia use automated speed camera enforcement.12 See above for current legislation.


  1. Venkatraman, V., Richard, C. M., Magee, K., & Johnson, K. (2021). Countermeasures that work: A highway safety countermeasures guide for State Highway Safety Offices. (Report No. DOT HS 813 097). Washington, DC: National Highway Traffic Safety Administration iconexternal icon
  2. Insurance Institute for Highway Safety, & Highway Loss Data Institute. (2021). Speed. icon. Accessed on 1/27/2022.
  3. National Highway Traffic Safety Administration. (2021). Quick facts 2019. (Report No. DOT HS 813 124). icon
  4. Baum, H. M., Wells, J. K., & Lund, A. K. (1991). The fatality consequences of the 65 mph speed limits, 1989. Journal of Safety Reseach, 22(4), 171–177. icon
  5. Farmer, C. M. (2017). Relationship of traffic fatality rates to maximum state speed limits. Traffic Injury Prevention, 18(4), 375–380. icon
  6. Wilson, C., Willis, C., Hendrikz, J. K., Le Brocque, R., & Bellamy, N. (2010). Speed cameras for the prevention of road traffic injuries and deaths. Cochrane Database of Systematic Reviews, (11). icon
  7. Kloeden, C., Mackenzie, J., & Hutchinson, T. (2018). Analysis of crash data from safety camera intersections in South Australia. (CASR143). Adelaide, South Australia, Australia: Department of Planning, Transport and Infrastructure icon
  8. Hu, W., & McCartt, A. T. (2016). Effects of automated speed enforcement in Montgomery County, Maryland, on vehicle speeds, public opinion, and crashes. Traffic Injury Prevention, 17 Suppl 1, 53-58. icon
  9. Insurance Institute for Highway Safety, & Highway Loss Data Institute. (2022). Automated enforcement laws. icon. Accessed on 1/27/2022.
  10. Kimley-Horn, & Governors Highway Safety Association. (2021). Equity in highway safety enforcement and engagement programspdf iconexternal icon. Governors Highway Safety Association
  11. CT Humanities. (2020). Setting speed limits – today in history: May 21. icon. Accessed on 1/26/2022.
  12. Insurance Institute for Highway Safety, & Highway Loss Data Institute. (2022). U.S. Communities using speed cameras. icon. Accessed on 1/27/2022.