Speed limit enforcement

The use of speed limits predates both motorized vehicles and enforcement of the laws. Facing the invention of the automobile, many nations enacted speed limit laws, and appropriate measures to enforce them.{{cite book|title=Criminal on the Road: A Study of Serious Motoring Offences and Those Who Commit Them|publisher=Routledge|year=1964|isbn=0415264162|page=64}} The Locomotive Acts in the UK set speed limits for vehicles, and later codified enforcement methods. The first Locomotive Act, passed in 1861, set a speed limit of {{Convert|10|mph}} in uninhabited areas, and {{Convert|5|mph}} within towns. This act also included the value of fines for violations of the law.

Stricter regulations came in the Locomotive Act 1865, which required a man with a red flag to walk {{convert|60|yd|m}} ahead of qualifying powered vehicles. The distance ahead of the pedestrian crew member was reduced to {{convert|20|yards}} in 1878 and the vehicles were required to stop on the sight of a horse.{{cite web

|title = MVRUS – Legislation: A summary of important legislation

|publisher = UK Department of the Environment

|url = http://www.roadsafetyni.gov.uk/index/road_safety_education/teacherzone-home/teacherzone-mvrus/mvrus-legislation.htm

|url-status = dead

|archive-url = https://web.archive.org/web/20090903023641/http://www.roadsafetyni.gov.uk/index/road_safety_education/teacherzone-home/teacherzone-mvrus/mvrus-legislation.htm

|archive-date = 3 September 2009

|df = dmy-all

}} The speed limit was effectively redundant as vehicle speeds could not exceed the speed at which a person could walk.

By 1895, some drivers of early lightweight steam-powered autocars assumed that these would be legally classed as a horseless carriage and would therefore be exempt from the need for a preceding pedestrian. A test case was brought by motoring pioneer John Henry Knight, who was subsequently convicted of using a locomotive without a licence.{{cite web|url=http://weyriver.co.uk/theriver/places_2_farnham.htm|title=History of Farnham|access-date=26 April 2010}} The Locomotives on Highways Act 1896 lifted some of the restrictions introduced by the 1865 Act, notably raising the speed limit for "light locomotives" under three tonnes to {{convert|14|mph|km/h}}. The speed limit was lifted again by the Motor Car Act 1903 to {{convert|20|mph|km/h}}.

A royal commission on motorcars in the UK reported in 1907 and raised concerns about the manner in which speed traps were being used to raise revenue in rural areas rather than being used to protect lives in towns. In parliamentary debates at the time it was observed that "Policemen are not stationed in the villages where there are people about who might be in danger, but are hidden in hedges or ditches by the side of the most open roads in the country" and were "manifestly absurd as a protection to the public, and they are used in many counties merely as a means of extracting money from the passing traveller in a way which reminds one of the highwaymen of the Middle Ages".{{cite web|url=https://api.parliament.uk/historic-hansard/commons/1906/may/24/royal-commission-on-motor-cars|title=Debate on the Royal Commission on Motor Cars|work=Parliamentary Debates (Hansard)|date=24 May 1906|access-date=17 April 2010}}{{cite web|url=https://api.parliament.uk/historic-hansard/lords/1907/jul/16/motor-car-legislation|title=MOTOR CAR LEGISLATION|work=Parliamentary Debates (Hansard)|date=16 July 1907|access-date=17 April 2010|quote=I regard the abolition of the speed limit as the most important recommendation of the Royal Commission... Policemen are not stationed in the villages where there are people about who might be in danger, but are hidden in hedges or ditches by the side of the most open roads in the country... I am entirely in sympathy with what the noble Earl said with regard to police traps. In my opinion they are manifestly absurd as a protection to the public, and they are used in many counties merely as a means of extracting money from the passing traveller in a way which reminds one of the highwaymen of the Middle Ages.}}

In 1905 The Automobile Association was formed to help motorists avoid police speed traps.{{cite web|url=http://www.theaa.com/aboutaa/history.html|title=About us|publisher=The AA|access-date=26 February 2010}} Chief Justice, Lord Alverston brought a test court case in 1910 (Betts v Stevens) against an Automobile Association patrolman and a potentially speeding motorist—the judge ruled that where a patrolman signals to a speeding driver to slow down and thereby avoid a speed trap, that person would have committed the offence of "obstructing an officer in the course of his duty" under the Prevention of Crimes Amendment Act 1885.JA Coutts, [https://www.jstor.org/stable/1091811 'Obstructing the Police'] (1956) 19 MLR 411{{cite web|url=http://www.swarb.co.uk/lisc/RdTrf19001929.php|title=Road Traffic – 1900– 1929 |publisher=swarb.co.uk|access-date=27 February 2010}} Subsequently, the organisation developed a coded warning system which was used until the 1960s whereby a patrolman would always salute the driver of a passing car that displayed a visible AA badge unless there was a speed trap nearby, on the understanding that their officers could not be prosecuted for failing to salute.{{cite web |title=AA ballots on first strike in 105 years |website=The Daily Telegraph |date=3 February 2010 |archive-url=https://web.archive.org/web/20230126083050/https://www.telegraph.co.uk/finance/newsbysector/industry/7141302/AA-ballots-on-first-strike-in-105-years.html |archive-date=2023-01-26 |url-status=live |url=https://www.telegraph.co.uk/finance/newsbysector/industry/7141302/AA-ballots-on-first-strike-in-105-years.html}}

Gatsometer BV, founded in 1958 by rally driver Maurice Gatsonides, produced the 'Gatsometer' which was described as "a revolutionary speed-measuring device".{{cite web|url=http://www.gatso.nl/web_en/history|title=History|publisher=Gatsometer|access-date=18 April 2010|archive-url=https://web.archive.org/web/20100310013704/http://www.gatso.nl/web_en/history|archive-date=10 March 2010|url-status=dead}} Developed initially for improving his race times,{{Citation needed|date=April 2010}} it was later marketed as police speed enforcement tool. Gatsometer claims to have developed the first radar for use with road traffic in 1971, but this claim is undermined by evidence that radar detectors were already for sale in 1967. Gatsometer BV produced the world's first mobile speed traffic camera in 1982.{{cite web|url=https://api.parliament.uk/historic-hansard/written-answers/1967/mar/02/radar-speed-trap-warning-apparatus#S5CV0742P0_19670302_CWA_107|title=Radar Speed Trap Warning Apparatus (Licence)|work=Parliamentary Debates (Hansard)|access-date=25 April 2010|date=2 March 1967|quote=a pocket-sized instrument is being produced by Marchant House Limited of New Street, Oadby, Liecester, to be used in motor vehicles to give instant warning of a police radar speed trap ... Anyone wishing to use this type of apparatus would require a licence under the Wireless Telegraphy Act, 1949. The firm in question has recently been informed that I am not prepared to issue a licence for such purposes}}

VASCAR was in use in North Carolina, New York and Indiana by February 1968.{{Cite magazine

| date = 9 February 1968 | title = The Highway: Versatile VASCAR

| magazine = Time

| url = http://www.time.com/time/magazine/article/0,9171,844388,00.html

| archive-url = https://web.archive.org/web/20101029093022/http://www.time.com/time/magazine/article/0,9171,844388,00.html

| url-status = dead

| archive-date = 29 October 2010

}}

Kevin Richardson proposed the idea of rewarding drivers travelling at or below the posted limit with a cash lottery, funded by the fines on speeding drivers. This was demonstrated in Stockholm, Sweden, in November 2010.{{cite news|last=Schultz|first=Jonathan|date=30 November 2010|title=Speed Camera Lottery Wins VW Fun Theory Contest|work=The New York Times|url=http://wheels.blogs.nytimes.com/2010/11/30/speed-camera-lottery-wins-vw-fun-theory-contest/}}

File:Polizei laser messung.jpg checking speed with a tripod-mounted LIDAR speed gun]]

Speed limits were originally enforced by manually timing or "clocking" vehicles travelling through "speed traps" defined between two fixed landmarks along a roadway that were a known distance apart; the vehicle's average speed was then determined by dividing the distance travelled by the time taken to travel it. Setting up a speed trap that could provide legally satisfactory evidence was usually time-consuming and error-prone, as it relied on its human operators.{{Citation needed|date=April 2016}}

The method of enforcement can be classified by:

• measuring the instantaneous speed at a point or the average speed between two widely spaced points some minutes or hours apart
• temporary, moving or permanent location
• human operator or automated operation
• all vehicles measured like a census, or only a selected sample of vehicles.

{{See also|Automatic number plate recognition}}

VASCAR is a device that semi-automates the timing and average speed calculation of the original manually operated "speed trap". An observer on the ground, in a vehicle or in the air simply presses a button as a vehicle passes two landmarks that are a known distance apart, typically several hundred metres.

Automatic number plate recognition (ANPR) systems that use a form of optical character recognition read the vehicle's licence or registration plate. A computer system reads vehicle registration plates at two or more fixed points along a road, usually hundreds of meters or even kilometers apart, then uses the known distance between them to calculate a vehicle's average speed. From the mean value theorem, we know that the vehicle's speed must equal its average speed at some time between the measurements. If the average speed exceeds the speed limit, then a penalty is automatically issued.{{cite news|url=http://news.bbc.co.uk/1/hi/scotland/4681507.stm|work=BBC News|title=Specs spies on speeding motorists|date= 14 July 2005|access-date=31 May 2008}}

Police in some countries like France have been known to prosecute drivers for speeding, using an average speed calculated from timestamps on toll road tickets.{{cite book|url=https://books.google.com/books?id=Hqb4Uxf3xlQC|title=Insight Guide: French Riviera|author=Brian Bell|page=318|publisher=Langenscheidt Publishers|year=2001|isbn=978-1-58573-148-0}}

Speed enforcement using average speed measurement is expressly prohibited in California.[https://www.dmv.ca.gov/portal/dmv/detail/pubs/vctop/vc/d17/c3/a1/40802 CVC 40802 Speed Traps], [https://www.dmv.ca.gov/portal/dmv/detail/pubs/vctop/vc/d17/c3/a1/40801 CVC 40801 Speed Trap Prohibition]

File:Din Fart (2012, ubt).jpg

File:Traffic Speed Interceptor - Vehicles with speed camera used by Bangalore Police, India.jpg Police, India]]

Instantaneous speed cameras measure the speed at a single point. These may either be a semi-permanent fixture or be established on a temporary basis. A variety of technologies can be used:

• Radar speed guns use a microwave signal that is directed at a vehicle; the Doppler effect is used to derive its speed.
• LIDAR speed guns utilize the time of flight of laser pulses to make a series of timestamped measurements of a vehicle's distance from the laser; the data is then used to calculate the vehicle's speed.{{Cite patent|country=US|number=5521696|pubdate=1996-05-28|title=Laser-based speed measuring device|assign1=Laser Technology Inc.|inventor1-last=Dunne|inventor1-first=Jeremy G.}}
• Sensors embedded in the roadway in pairs, for example electromagnetic induction or Piezo-electric strips a set distance apart.{{cite web|url=http://www.safermotoring.co.uk/PoliceEnforcementCameras.html|title=Police Speed Enforcement Cameras|work=Safer motoring|access-date=19 April 2010}}
• Infra-red light sensors located perpendicular to the road, e.g. TIRTL.
• In the early days of vehicle speed enforcement, the police primarily used two pneumatic road tubes placed a short distance apart. This measures the time vehicles take to travel between the two tubes, and the travel speed can be derived from it. The short distance between the two tubes was called a "trap" and hence the colloquial term "speed trap" that describes any police speed monitoring location.{{cite book |last1=Roess |first1=Roger P. |last2=Prassas |first2=Elena S. |last3=McShane |first3=William R. |title=Traffic engineering |date=2004 |publisher=Pearson/Prentice Hall |location=Upper Saddle River, N.J |isbn=9780131424715 |page=205 |edition=3rd}}

Officers in some jurisdictions may also use pacing, particularly where a more convenient radar speed measuring device is not available—a police vehicle's speed is matched to that of a target vehicle, and the calibrated speedometer of the patrol car used to infer the other vehicle's speed.{{cite book|url=https://books.google.com/books?lr|page=15|volume= 2004|isbn=978-0-13-114957-1|publisher=Pearson Prentice Hall|year=2004|title=Police Technology}}

In recent years many jurisdictions began using cameras to record violators. These devices detect vehicles that are exceeding the speed limit and take photos of these vehicles' license plates. A ticket is then mailed out to the registered owner.{{Citation needed|date=April 2016}}

Some jurisdictions, such as Australia and Ohio, allow prosecutions based on a subjective speed assessment by a police officer.{{cite web | url=http://www.cleveland.com/open/index.ssf/2010/06/police_officers_visual_estimat.html | title=Police officer's visual estimate of speed is enough for a conviction, Ohio Supreme Court rules| date=2 June 2010}}{{cite web|url=http://www.cis.org.au/publications/policy-magazine/article/2374-feature-speed-traps-saving-lives-or-raising-revenue|title=Speed Traps: Saving Lives or Raising Revenue?|author=Alan Buckingham|date=17 October 2003|access-date=27 April 2010}}

In the future, there is the potential to track speed limit compliance via GPS black boxes for recidivist speeders identified in the Australian National Road Safety Strategy 2011 - 2020 section on Intelligent speed adaptation.

{{main|Traffic enforcement camera}}

• Aside from the issues of legality in some countries and states and of sometime opposition the effectiveness of speed cameras is very well documented. The introduction to [http://www.racfoundation.org/assets/rac_foundation/content/downloadables/efficacy_of_speed_cameras_allsop_181110.pdf The Effectiveness of Speed Cameras A review of evidence] by Richard Allsop includes the following in the foreword by Stephen Glaister, director of the RAC (Royal Automobile Club). "While this report fully lays out the background to the introduction of speed cameras and the need for speed limits, its job is not to justify why the national limits are what they are; a review of speed limits to see whether they are soundly based is for another day. What it has done is to show that at camera sites, speeds have been reduced, and that as a result, collisions resulting in injuries have fallen. The government has said that a decision on whether speed cameras should be funded must be taken at a local level. With the current pressure on public funds, there will be – indeed there already are – those who say that what little money there is can be better spent. This report begs to differ. The devices are already there; they demonstrate value for money, yet are not significant revenue raisers for the Treasury; they are shown to save lives; and despite the headlines, most people accept the need for them. Speed cameras should never be the only weapon in the road safety armoury, but neither should they be absent from the battle."
• The 2010 Cochrane Review of speed cameras for the prevention of road traffic injuries and deaths{{cite journal|title=Speed cameras for the prevention of road traffic injuries and deaths.|last=Wilson|first=C |author2=Willis, Hendrikz |author3=Le Brocque, Bellamy|journal=The Cochrane Database of Systematic Reviews|year=2010|issue=10|pmid=20927736|doi=10.1002/14651858.CD004607.pub3|pages=CD004607|url=http://espace.library.uq.edu.au/view/UQ:224791/UQ224791_OA.pdf|editor1-last=Wilson|editor1-first=Cecilia}} reported that all 28 studies accepted by the authors found the effect of speed cameras to be a reduction in all crashes, injury crashes, and death or severe injury crashes. "Twenty eight studies measured the effect on crashes. All 28 studies found a lower number of crashes in the speed camera areas after implementation of the program. In the vicinity of camera sites, the reductions ranged from 8% to 49% for all crashes, with reductions for most studies in the 14% to 25% range. For injury crashes the decrease ranged between 8% and 50% and for crashes resulting in fatalities or serious injuries the reductions were in the range of 11% to 44%. Effects over wider areas showed reductions for all crashes ranging from 9% to 35%, with most studies reporting reductions in the 11% to 27% range. For crashes resulting in death or serious injury reductions ranged from 17% to 58%, with most studies reporting this result in the 30% to 40% reduction range. The studies of longer duration showed that these positive trends were either maintained or improved with time. Nevertheless, the authors conceded that the magnitude of the benefit from speed cameras "is currently not deducible" due to limitations in the methodological rigor of many of the 28 studies cited, and recommended that "more studies of a scientifically rigorous and homogenous nature are necessary, to provide the answer to the magnitude of effect."
• According to the 2003 NCHRP study on Red Light Running (RLR), "RLR automated enforcement can be an effective safety countermeasure....[I]t appears from the findings of several studies that, in general, RLR cameras can bring about a reduction in the more severe angle crashes with, at worst, a slight increase in less severe rear-end crashes.{{cite book|title=NCHRP Synthesis 310|author=Hugh McGee|page=12|publisher=National Cooperative Highway Research Program|year=2003}} However it noted that "there is not enough empirical evidence based on proper experimental design procedures to state this conclusively."
• The 2010 report, "The Effectiveness of Speed Cameras A review of evidence",{{cite web |url=http://www.racfoundation.org/assets/rac_foundation/content/downloadables/efficacy_of_speed_cameras_allsop_181110.pdf |title=The Effectiveness of Speed Cameras |website=Racfoundation.ortg |access-date=30 June 2016 |url-status=live |archive-url=https://web.archive.org/web/20160415114909/http://www.racfoundation.org/assets/rac_foundation/content/downloadables/efficacy_of_speed_cameras_allsop_181110.pdf |archive-date=15 April 2016 }} by Richard Allsop concludes "The findings of this review for the RAC Foundation, though reached independently, are essentially consistent with the Cochrane Review conclusions. They are also broadly consistent with the findings of a meta-analysis reported in the respected Handbook of Road Safety Measures, of 16 studies, not including the four-year evaluation report, of the effects of fixed cameras on numbers of collisions and casualties."
• A recent study{{when|date=March 2019}} conducted in Alabama reveals that Red Light Cameras (RLCs) seem to have a slight impact on the clearance lost time; the intersections equipped with RLCs are half a second less in use compared with those without cameras; and highway capacity manual estimates a shorter lost time and thus may overestimate the intersection's capacity.{{cite journal |last1=Baratian-Ghorghi |first1=Fatemeh |last2=Zhou |first2=Huaguo |last3=Wasilefsky |first3=Isaac |year=2015 |title=Effect of Red-Light Cameras on Capacity of Signalized Intersections |journal=Journal of Transportation Engineering |volume=142 |page=04015035 |doi=10.1061/(ASCE)TE.1943-5436.0000804 }}
• In 2001 the Nottingham Safety Camera Pilot achieved "virtually complete compliance" on the major ring road into the city using average speed cameras,{{cite web|url=https://publications.parliament.uk/pa/cm200102/cmselect/cmtlgr/557/557ap65.htm|title=Annex 6 TECHNOLOGY FOR ENFORCEMENT|quote=A notable example is in the Nottingham Safety Camera Pilot where virtually complete compliance was achieved on the major ring road into the city}} across all Nottinghamshire SPECS installations, KSI (Killed / Seriously Injured) figures have fallen by an average of 65%.{{cite web|url=http://www.speedcheck.co.uk/images/Nottingham_Case_Study.pdf|title=Permanent Casualty Reduction Scheme|quote=Across all Nottinghamshire SPECS installations, KSI figures have fallen by an average of 65%}}
• In 2003 Injury Prevention reported that speed cameras were effective at reducing accidents and injuries and recommended wider deployment.{{cite journal|title=Are mobile speed cameras effective? A controlled before and after study|volume=9|issue=4|pages=302–306|author=S M Christie|author2=R A Lyons|author3=F D Dunstan|author4=S J Jones in Injury Prevention|name-list-style=amp|journal= Injury Prevention|quote=Camera sites had lower than expected numbers of injurious crashes up to 300 metres using circles and up to 500 metres using routes. Routes methods indicated a larger effect than the circles method except in the 100 metres nearest sites. A 500-metre route method was used to investigate the effect within strata of time after intervention, time of day, speed limit, and type of road user injured. The number of injurious crashes after intervention was substantially reduced|doi=10.1136/ip.9.4.302|pmid=14693888|year=2003|pmc=1731028}} In February 2005 the British Medical Journal reported that speed cameras were an effective intervention in reducing road traffic collisions and related casualties, noting however that most studies to date did not have satisfactory control groups.{{cite journal |author1=Paul Pilkington |author2=Sanjay Kinra |name-list-style=amp | title=Effectiveness of speed cameras in preventing road traffic collisions and related casualties: systematic review | journal= BMJ| year=2005 | volume=330 | issue=12 February | pages=331–334 | doi=10.1136/bmj.38324.646574.AE | pmid=15653699|quote=Existing research consistently shows that speed cameras are an effective intervention in reducing road traffic collisions and related casualties. The level of evidence is relatively poor, however, as most studies did not have satisfactory comparison groups or adequate control for potential confounders. Controlled introduction of speed cameras with careful data collection may offer improved evidence of their effectiveness in the future. | pmc=548724}} In 2003 Northumbria Police's Acting Chief Inspector of motor patrols suggested that cameras didn't reduce casualties but did raise revenue – an official statement from the police force later re-iterated that speed cameras do reduce casualties.{{cite news |url=http://icnewcastle.icnetwork.co.uk/0100news/thejournal/content_objectid=13555072_method=full_siteid=50081_headline=-Cameras-are-for-cash-name_page.html |title=Cameras are for cash |publisher=The Journal |date=25 October 2003|access-date=31 March 2008}}
• In December 2005 the Department for Transport published a four-year report into Safety Camera Partnerships which concluded that there was a 22% reduction in personal injury collisions and 42% fewer people being killed or seriously injured following the installation of cameras.{{cite report | publisher = UK Department for Transport | title = The National Safety Camera Programme: Four Year Evaluation Report | year = 2005 | url = http://www.dft.gov.uk/pgr/roadsafety/speedmanagement/nscp/nscp/thenationalsafetycameraprogr4597 | access-date = 13 June 2018 | archive-url = https://web.archive.org/web/20100329032402/http://www.dft.gov.uk/pgr/roadsafety/speedmanagement/nscp/nscp/thenationalsafetycameraprogr4597 | archive-date = 29 March 2010 | url-status = dead | df = dmy-all }} The Times reported that this research showed that the department had been previous exaggerating the safety benefits of speed cameras but that the results were still 'impressive'.{{cite news|url=http://www.timesonline.co.uk/article/0,,2-1934085,00.html|archive-url=https://web.archive.org/web/20081007022836/http://www.timesonline.co.uk/article/0,,2-1934085,00.html|url-status=dead|archive-date=7 October 2008|title=Speed camera benefits overrated|work=The Times|date=16 December 2005 | location=London | first=Ben | last=Webster |quote=The main report says that fixed cameras reduce deaths and serious injuries by 50 percent and mobile cameras by 35 percent. It calculates that cameras prevent 1,745 deaths or serious injuries a year across Britain. But once the regression to the mean was taken into account, fixed cameras were found to reduce deaths and serious injuries by only 873, or 24 percent for fixed and 17 percent for mobile cameras. While still impressive, these reductions are lower than could be achieved by other road safety measures.}}
• A report published by the RAC Foundation in 2010 estimated that an additional 800 more people a year could be killed or seriously injured on the UK's roads if all speed cameras were scrapped.{{cite news|url=https://www.bbc.co.uk/news/uk-11826295|title=RAC Foundation report backs speed camera safety benefit|date=24 November 2010 | work=BBC News}} A survey conducted by The Automobile Association in May 2010 indicated that speed cameras were supported by 75% of their members.{{cite web|url=http://www.admiral.com/newsArticles/4520/Speed-camera-support-at-all-time-high|title=Speed camera support 'at all-time high'|publisher=Admiral|quote=Support for speed cameras is running at an all-time high, a poll by the AA has suggested. According to the motoring organisation's survey of members in October, 75% now believe that the use of speed cameras is 'acceptable' – including 30% who believe their use is 'very acceptable'. This compares with a 69% approval rating in a poll conducted in November last year, and is the highest level reached in ten years of monitoring public sentiment for the devices, the AA says. }}
• The town of Swindon abandoned the use of fixed cameras in 2009, questioning their cost-effectiveness with the cameras being replaced by vehicle-activated warning signs and enforcement by police using mobile speed cameras:{{cite news|url=http://news.bbc.co.uk/1/hi/england/wiltshire/8177247.stm|title=Town ditches fixed speed cameras|work=BBC News | date=31 July 2009}} in the nine months following the switch-off there was a small reduction in accident rates which had changed slightly in similar periods before and after the switch off (Before: 1 fatal, 1 serious and 13 slight accidents. Afterwards: no fatalities, 2 serious and 12 slight accidents).{{Cite news|url=https://www.telegraph.co.uk/motoring/news/7931842/Speed-camera-switch-off-sees-fewer-accidents.html|title=Speed camera switch-off sees fewer accidents|author=David Barrett|work=The Daily Telegraph|location=London|date=7 August 2010|access-date=30 June 2016|url-status=live|archive-url=https://web.archive.org/web/20160918062810/http://www.telegraph.co.uk/motoring/news/7931842/Speed-camera-switch-off-sees-fewer-accidents.html|archive-date=18 September 2016}} The journalist George Monbiot claimed that the results were not statistically significant highlighting earlier findings across the whole of Wiltshire that there had been a 33% reduction in the number of people killed and seriously injured generally and a 68% reduction at camera sites during the previous 3 years.{{cite web |url=http://www.monbiot.com/archives/2010/07/26/tory-boy-racers/ |title=Tory Boy Racers | George Monbiot |website=Monbiot.com |date=26 July 2010 |access-date=30 June 2016 |url-status=live |archive-url=https://web.archive.org/web/20110130020242/http://www.monbiot.com/archives/2010/07/26/tory-boy-racers/ |archive-date=30 January 2011 }} In 2012, the town had the fewest accident rates per 1,000 registered vehicles: a result linked by the Local Authority Member for Council Transformation, Transport and Strategic Planning to the removal of speed cameras and resultant additional funding for road safety, alongside close working with the police.{{cite web |author=Katie Bond |url=http://www.thisiswiltshire.co.uk/news/9604736.Town_tops_league_for_safest_driving/ |title=Town tops league for safest driving |website=Thisiswiltshire.co.uk |date=21 March 2012 |access-date=30 June 2016 |url-status=live |archive-url=https://web.archive.org/web/20160815222806/http://www.thisiswiltshire.co.uk/news/9604736.Town_tops_league_for_safest_driving/ |archive-date=15 August 2016 }}

File:Gatso.camera.arp.jpg

While digital cameras can be used as the primary means of speed detection when combined with automatic number plate recognition (ANPR) average-speed camera systems, their use is more commonly restricted to evidence gathering where speeding offences are detected by various other types of sensors such as Doppler radar, piezo strips, infrared or laser devices.{{Citation needed|date=May 2010}}

Photographs are typically time-stamped by a high-resolution timing device so that a vehicle's speed can be checked manually after the fact if necessary using the secondary method of calculating its speed between a series of calibrated lines painted on the road surface.{{citation needed|date=April 2020}}

The change from analogue "wet film" to digital technology has revolutionised speed cameras, particularly their maintenance and the back-office processing required to issue penalty notices. Images from digital cameras can be uploaded in seconds to a remote office over a network link, while optical character recognition software can record vehicle registration numbers.{{cite report|url=http://www.monash.edu.au/muarc/reports/muarc277.pdf|title=Development of Strategies for Best Practice in Speed Enforcement in Western Australia|publisher=Monash University Accident Research Centre|date=10 June 2008|author=Max Cameron|page=6}}

Types of camera include Gatso, Truvelo Combi and D-cam.

File:Radar Detector. canada. Escort Passport 8500 x50 blue 3635.jpg and LIDAR detector]]

Some drivers use passive radar detectors or LIDAR detectors to detect police radar or LIDAR signals, with the intention of avoiding or evading prosecution by slowing down before entering an enforcement zone. The legal standing of these type of devices varies by jurisdiction. For example, they are legal in most of the United States, but not in most of Canada.{{cite web|url=http://www.whistlergroup.com/faq-detectors-answers.asp#19|title=Radar detectors FAQ|access-date=17 September 2010|publisher=Whistler Group|archive-url=https://web.archive.org/web/20100904025122/http://www.whistlergroup.com/faq-detectors-answers.asp#19|archive-date=4 September 2010|url-status=dead}} Active devices might also be used—in this instance, radar or LIDAR signals are typically jammed with counter emissions. These devices are more frequently illegal than passive devices.

Drivers may flash their lights to approaching drivers to warn them of a speed trap. The legal standing of this action also varies by jurisdiction. In the United States, it is common for motorists with Citizen's Band (CB) radios to report the location of speed traps over the CB radio to other motorists.{{cite web

|url=https://toronto.ctvnews.ca/driver-upset-after-ticketed-for-flashing-headlights-1.273772

|title=Driver upset after ticketed for flashing headlights

|date=30 January 2008

|access-date=17 September 2009

|publisher = CFTO-TV

|quote=A Toronto man is upset he was ticketed for flashing his headlights to tip off oncoming drivers of a radar speed trap, especially since police admit the act is not illegal.'

}}

In 2006, the UK Automobile Association controversially published a road map that included the location for thousands of speed cameras—the first time such information was available in printed form,{{cite news|url=https://www.independent.co.uk/news/uk/home-news/aa-causes-fury-by-publishing-its-firstever-map-of-speed-cameras-496575.html |archive-url=https://ghostarchive.org/archive/20220524/https://www.independent.co.uk/news/uk/home-news/aa-causes-fury-by-publishing-its-firstever-map-of-speed-cameras-496575.html |archive-date=24 May 2022 |url-access=subscription |url-status=live|title=AA causes fury by publishing its first-ever map of speed cameras|date=26 June 2005|work=The Independent |quote=A controversial decision by the AA to publish its first map of speed traps has provoked a storm of protest from safety experts, who accuse the organisation of encouraging motorists to break the law.|access-date=17 April 2010 | location=London | first=Steve | last=Bloomfield}} although more accurate and frequently updated GPS-based information was freely available for some time before that.

Mobile applications such as Njection, Trapster, and Waze provide mobile information to drivers on speed traps and traffic conditions. These applications rely on users to keep the databases current.{{citation|url=https://www.nytimes.com/2008/05/04/business/04bug.html?ref=business|title=The Camera That Wears a Badge|last=Sharkey|first=Joe|work=New York Times|date=4 May 2008|access-date=7 July 2011}} In addition to mobile applications that might be considered evasion-centric, there are other similar mobile applications that are classified as Intelligent speed adaptation technologies that are considered too compliance centric and in Australia both National and State Road Safety Strategies encourage the adoption of such technologies.

In Belgium, Germany, and the Netherlands, the location of speed traps are announced using the Highway location marker at regular intervals on major radio stations. Conversely, announcing the exact location of a speed trap is illegal in France.

Groups such as the National Motorists Association define speed trap more narrowly as a place where "traffic enforcement is focused on extracting revenue from drivers instead of improving safety".{{cite web |url=http://www.motorists.org/speed-traps/definition |title=What is a Speed Trap? | Speed Traps |access-date=11 October 2015 |url-status=dead |archive-url=https://web.archive.org/web/20150828051846/http://www.motorists.org/speed-traps/definition |archive-date=28 August 2015 }}

When highway speed limits drop suddenly just as the road enters a municipality that collects large amounts of revenue from traffic tickets, a safety hazard can be introduced, and efforts have been made in the U.S. to ban this practice.{{cite news|author=Brad Tuttle|title=End of the Road for Speed Traps?|work=Time magazine|date=2 September 2013|url=https://business.time.com/2013/09/02/end-of-the-road-for-speed-traps/}}

Some police forces have even been forced to disband as a result of overzealous enforcement.{{cite news|title=Florida 'speed trap' town disbands police force|agency=Associated Press|date=2 October 2014|url=https://www.theguardian.com/world/2014/oct/02/florida-speed-trap-town-disbands-police-force}}

However, a meta-analysis of studies finds automated ticketing machines that enforce speed limits may have reduced the number of traffic injuries and deaths.{{cite journal |author= Wilson C, Willis C, Hendrikz JK, Le Brocque R, Bellamy N |title= Speed cameras for the prevention of road traffic injuries and deaths |journal=Cochrane Database of Systematic Reviews |volume=2010 |issue=11 |pages= CD004607 |year=2010 |pmid= 20927736 |doi=10.1002/14651858.CD004607.pub3 |url=http://onlinelibrary.wiley.com/o/cochrane/clsysrev/articles/CD004607/frame.html|last2= Willis |last3= Hendrikz |last4= Le Brocque |last5= Bellamy |url-access= subscription }}

{{Further|topic=the group, Front National Anti Radar in France|FNAR}}

Speed limits may not be enforced for speeds close to the legal limit. In the United States, speeding enforcement tolerance is usually up to the discretion of the arresting officer. Some states (such as Pennsylvania and Florida) have official tolerances.{{Cite web|url=https://www.legis.state.pa.us/cfdocs/legis/LI/consCheck.cfm?txtType=HTM&ttl=75&div=0&chpt=33|title=Title 75|website=The official website for the Pennsylvania General Assembly.}}

As older vehicle construction regulations allowed a speedometer accuracy of +/- 10%, in the United Kingdom ACPO guidelines recommend a tolerance level of the speed limit "×10% +2 mph" (e.g., a maximum tolerance in a {{convert|30|mi/h|km/h|-1|abbr=on}} zone of 30 + (30 × 10% = 3) + 2 = 35 mph).{{cite web|title=Speed Enforcement|url=http://www.cps.gov.uk/legal/p_to_r/road_traffic_offences_guidance_on_fixed_penalty_notices/#speed|work=cps.gov.uk|publisher=CPS|access-date=3 February 2014}}

In Germany, at least a 3 km/h tolerance (3% of measured speed when speeding over 100 km/h) in favor of the offender is always deducted. This tolerance can increase up to 20% depending on the method of measurement.{{cite web |url=http://www.verkehrslexikon.de/Module/GSToleranz.php |title=Toleranzabzüge bei standardisierten Messverfahren zur Feststellung von Geschwindigkeitsverstößen |website=verkehrslexikon.de |access-date=5 December 2014 |language=de}} Fines for speeding depend on how high above the speed limit the measured speed is and where the offense occurred. Speeding in built-up areas invariably carries higher fines than outside city limits. While fines for minor offenses tend to be moderate, speeds in excess of {{convert|20|km/h|0|abbr=on}} above the limit in built-up areas result in distinctly higher fines and points on the driver's license, and, depending on the speed at which the offender was clocked, may lead to a driving ban of at least one month.{{cite web |url=https://www.bussgeldkatalog.org/geschwindigkeitsueberschreitung/ |title=Geschwindigkeitsüberschreitung |website=bussgeldkatalog.org |access-date=5 December 2014 |language=de}}

The state of Victoria in Australia allows for only a {{convert|3|km/h|mph|abbr=on}} tolerance for mobile speed cameras and {{convert|2|km/h|mph|abbr=on}} for fixed cameras on the basis that, although the increased risk is lower, there are very many more drivers involved, which creates a substantial risk across the road network.{{cite report|url=http://archive.audit.vic.gov.au/reports_par/agp11602.html |title=Making travel safer: Victoria's speed enforcement program |publisher=Victorian Auditor General |date=20 July 2006 |access-date=18 October 2009 |url-status=dead |archive-url=https://web.archive.org/web/20091002002021/http://archive.audit.vic.gov.au/reports_par/agp11602.html |archive-date=2 October 2009 }} An alternative view is that police devices are accurate to 1 km/h, and that a 2–3 km/h tolerance is the minimum margin that police require to defeat any challenge in court regarding the accuracy of their speed measurement equipment.{{cite web|url=http://www.trafficlaw.com.au/speedos.html|title=Inaccurate Speedos|publisher=trafficlaw.com.au|access-date=28 April 2010|author=S.P. Hardy}} Speed tolerance in New South Wales was an election issue in 2011, following a move by the budget committee of the previous Labor state government to abolish the 3 km/h margin in order to increase revenue.{{cite news|url=http://www.theage.com.au/national/greater-leeway-for-speeding-drivers-20110330-1cgcy.html|title=Greater Leeway for Speeding Drivers|author=Alexandra Smith|work=The Age |location=Australia|date=31 March 2011|access-date=16 June 2011}}

In Mexico, the maximum speed limit is {{convert|80|km/h|mph}} on urban freeways on other urban roads. However, fines are only given when speeding above {{convert|90|km/h|mph}}, thus giving a {{convert|10|km/h|mph}} tolerance. The Mexican highway patrol (Mexico City) and traffic law enforcement officers (Guadalajara) may enforce speed laws only when a car is speeding above reasonable speeds in regard of the amount of traffic. Maximum speed for all Mexican highways is {{convert|110|km/h|mph}}. Speeding fines are given to those going {{convert|130|km/h|mph}} and up to {{convert|220|km/h|mph}}. Police may however place a squad car as a pace car so drivers behind cannot exceed {{convert|100|km/h|mph}}; this is common during Summer and Winter holiday season.{{citation needed|date=June 2018}}

Speed limit policy can affect enforcement. According to a 1994 report by the AASHTO, "experience has shown that speed limits set arbitrarily below the reasonable and prudent speed perceived by the public are difficult to enforce, produce noncompliance, encourage disrespect for the law, create unnecessary antagonism toward law enforcement officers, and divert traffic to lesser routes".{{cite web|url=http://www.ibiblio.org/rdu/aashtosl.html|title=AASHTO Policy Resolution: The National Statutory Speed Limit|date=19 April 1994|publisher=American Association of State Transport Highway Officials|access-date=17 September 2009}}

A study of over 1,000 drivers caught speeding in the U.S. and in Canada examined factors that predicted fines issued by police officers. In both countries, drivers were stopped for speeding on average 16 mph (26 km/h) over the speed limit and received fines of approximately US$144. As expected, drivers traveling at higher speeds over the limit received higher fines. What drivers said to the police also affected the amount of the fine. 46% percent of drivers in the study reported offering an excuse (e.g. "I didn't realize the speed I was driving"), which was the most common type of verbal response. Excuses, justifications, and denials did not reduce the amount of the fine. Almost 30% of drivers expressed remorse (e.g., "I'm sorry") and received a considerable reduction in fines. Offers of remorse were most effective at higher speeds over the limit. For example, American speeders who offered remorse for traveling at higher speeds over the limit (21 mph) received fines that were US$49 lower than drivers who were speeding the same amount, but did not offer an apology. Although this research indicated that apologies can be related to lower fines for speeding, most drivers who offered remorse were still punished to some degree. To maintain a relatively normal sample of speeders, a small percentage of drivers who reported extreme speeds (80 km/h (50 mph) or more over the limit) or very severe fines (US$500 or more) were excluded.{{cite journal|last=Day|first=M. V.|author2=Ross, M.|year=2011|title=The value of remorse: How drivers' responses to police predict fines for speeding|journal=Law and Human Behavior|volume=35|issue=3|pages=221–234|doi=10.1007/s10979-010-9234-4|pmid=20556494|s2cid=13262186}}

Authorities are not able to monitor every vehicle on every road—limited resources generally mean that enforcement needs to be targeted. A New Zealand study concluded that actual enforcement as well as the perceived chance of being caught both contributed to changes in drivers' behaviour.{{cite conference|url=https://books.google.com/books?id=Uq9x1ydR_1YC|title=Speed Management|conference=European Conference of Ministers of Transport at OECD/ECMT Transport Research Centre|page=155|isbn=978-92-821-0377-7|publisher=OECD Publishing|year=2006 }}

Many jurisdictions operate traffic violations reciprocity where non-resident drivers are treated like residents when they are stopped for a traffic offense that occurs in another jurisdiction. They also ensure that penalties such as demerit points and the ensuing increase in insurance premiums follow the driver home. The general principle of such interstate, inter-provincial, and/or international compacts is to guarantee the rule 'one license, one record.'

In 2001, Acme-Rent-a-Car in Connecticut controversially tried to use a contractual clause in the rental agreement to issue speeding fines to any of its customers that exceeded speed limits as detected by GPS tracking units its cars. The company actions were challenged and defeated in court.{{cite web |author=Lemos |first=Robert |date=2 July 2001 |title=State Puts Brakes on GPS Speeding Fines |url=http://news.cnet.com/State-puts-brakes-on-GPS-speeding-fines/2100-1040_3-269388.html |archive-url=https://web.archive.org/web/20121025165348/http://news.cnet.com/State-puts-brakes-on-GPS-speeding-fines/2100-1040_3-269388.html |archive-date=25 October 2012 |access-date=29 April 2010 |website=CNET}}{{cite journal|journal=ACME: An International Journal for Critical Geographies|volume=4|issue=1|pages=131–144 |issn=1492-9732|url=http://www.acme-journal.org/vol4/ADP.pdf|title=Critical GPS: Toward a New Politics of Location|first=Amy D.|last=Propen|publisher=Department of Rhetoric, University of Minnesota|date=10 June 2006|url-status=dead|archive-url=https://web.archive.org/web/20090509165113/http://www.acme-journal.org/vol4/ADP.pdf|archive-date=9 May 2009 }}

Doug Georgianni, 51, was shot as he operated a photo radar van on a Phoenix freeway and later died at a hospital.{{cite web |url=http://www.myfoxphoenix.com/story/18143227/photo-radar-van-driver-shot-to-death |title=Photo-Radar Van Driver Shot to Death |last1=Davenport |first1=Paul |date=20 April 2009 |website=MyFoxPhoenix.com |access-date=19 January 2014}}

Retribution attacks on photo enforcement equipment have become commonplace throughout the world.{{cite web|url=http://banthecams.org/20110315980/IRISH-NEWS-Speed-camera-van-target-of-suspected-firebomb-attack.html |title=Speed-camera van target of suspected firebomb attack|access-date=9 April 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110620190632/http://banthecams.org/20110315980/IRISH-NEWS-Speed-camera-van-target-of-suspected-firebomb-attack.html |archive-date=20 June 2011 }}{{cite web|last=Stern |first=Ray |url=http://blogs.phoenixnewtimes.com/valleyfever/2008/12/local_photo_enforcement_vandal.php |title=Local Photo Enforcement Vandalism is Child's Play Compared to Destruction of Speed Cameras Elsewhere – Phoenix News – Valley Fever |publisher=Blogs.phoenixnewtimes.com |date=1 December 2008 |access-date=24 May 2012}}{{cite web|url=http://www.thenewspaper.com/rlc/docs/2006/winnipegaudit.pdf |title=Microsoft Word - Photo Enforcement Final Report Feb 9 2006.doc |access-date=11 March 2019}}

{{Main|Road speed limit enforcement in Australia}}

In August 2005, in Sydney, a speed camera photograph was challenged on the basis that an MD5 cryptographic hash function used to protect the digital photograph from tampering was not robust enough to guarantee that it had not been altered. Magistrate Lawrence Lawson demanded that the Roads & Traffic Authority (RTA) produce an expert witness who could prove the photographs were tamper-proof, but the RTA was unable to provide such evidence. The defendant was acquitted and awarded court costs.{{cite news|url=http://www.theage.com.au/articles/2005/08/10/1123353368652.html|title=NSW Speed Cameras in Doubt|work=The Age|date=10 August 2005|access-date=28 April 2010 | location=Melbourne, Australia}}

In June 2011, the Government of New South Wales was reported to have raised {{A$|350}} million over the previous five years from speed cameras.{{Cite news |title='Cash cow' speed cameras raise $350m |date=2 June 2011 |work=Sydney Morning Herald |publisher=Fairfax Media |url=http://smh.drive.com.au/roads-and-traffic/cash-cow-speed-cameras-raise-350m-20110601-1fgw7.html |access-date=27 June 2011 |archive-url=https://web.archive.org/web/20110604115140/http://smh.drive.com.au/roads-and-traffic/cash-cow-speed-cameras-raise-350m-20110601-1fgw7.html |archive-date=4 June 2011 |url-status=dead }} The Roads Minister accused the previous Labor government of using speed cameras to raise revenue; the Auditor-General was therefore tasked with investigating all 141 fixed speed cameras in use throughout the state. Following the release of the report, 38 speed cameras, located primarily on highways, were switched off after the Auditor-General determined that they had no significant road safety benefit. The report found the majority of fixed-speed cameras had a proven road safety benefit. The report also concluded that it was "too early" to conclude if mobile speed cameras affected road safety, although early results indicated drivers might be speeding less. To address public concerns, the RTA would now monitor the effectiveness of individual fixed-speed cameras annually.[http://www.rta.nsw.gov.au/newsevents/downloads/minister_releases/110727-speed-camera-audit.pdf Report finds speed cameras are an effective safety tool] Media Release The Hon Duncan Gay MLC Minister for Roads and Ports 27 July 2011[http://www.caradvice.com.au/130070/nsw-government-switches-off-38-speed-cameras/ NSW Government switches off 38 speed cameras] Caradvice 27 July 2011 (includes locations of cameras turned off)

In 2010/11, the Government of South Australia raised A$114 million from speed limit enforcement activities.{{Cite news |title=PARLIAMENT is facing a renewed push for a top-level inquiry into the use of speed cameras |date=27 June 2011 |work=Adelaide Now |publisher=News Limited |url=http://www.adelaidenow.com.au/new-push-for-speed-camera-inquiry/story-e6frea6u-1226082460489 |access-date=27 June 2011}} The SA government are resisting moves by their opposition to commission an inquiry into whether speed cameras are being used effectively and efficiently: to improve road safety, to raise revenue, or both.

File:mobile speed camera.jpg. The camera is mounted on the passenger side dash, whilst the black box on the front is the radar unit.]]

In 2004, in a Poltech fixed speed camera on Melbourne's Western Ring Road recorded a four-cylinder Datsun 120Y sedan travelling at 158 km/h, but testing found this vehicle only capable of 117 km/h.{{cite web|title=Victoria's speed camera saga continues|url=http://www.abc.net.au/7.30/content/2004/s1121730.htm|work=The 7.30 Report|publisher=Australian Broadcasting Corporation|access-date=7 June 2011}} A Victorian state government inquiry found that maintenance and accuracy checks had not been done regularly.{{cite web|title=Government acts on fixed speed cameras|url=http://speedingticketpa.com/office-premier/|work=Media Release 14 May 2004|publisher=Office of the Premier|access-date=7 June 2011}}

Victoria achieved record-low road fatalities in both 2008 and 2009.{{cite news|title=State's road toll dips to its lowest on record|work=The Age |date=1 January 2009|url=http://www.theage.com.au/national/states-road-toll-dips-to-its-lowest-on-record-20081231-77y0.html | location=Melbourne, Australia| first=Jason | last=Dowling}}{{Cite news|title=Victoria's road toll at record low|work=The Age |date=27 December 2009|url=http://www.theage.com.au/national/victorias-road-toll-at-record-low-20091226-lfqp.html | location=Melbourne, Australia| first=Reid | last=Sexton}} Newspaper reports credited a coordinated and well-funded campaign that focused on higher risk young drivers, more aggressive policing, increased police activity, drink driving, and in 2009, a 50% increase in the use of mobile speed cameras.

After a growing number of complaints about incorrect and inappropriate fines, Victoria's Auditor-General plans to investigate whether speed cameras are being used primarily to raise revenue for the state government rather than to improve road safety.{{cite news |title=A-G to probe use and integrity of road cameras |date=25 May 2011 |work=The Age |location=Australia |publisher=Fairfax Media |url=http://www.theage.com.au/victoria/ag-to-probe-use-and-integrity-of-road-cameras-20110524-1f2jx.html?from=age_sb |access-date=14 June 2011}}

In June 2011, in Victoria, the road fatalities for the year so far was reported to be "significantly higher""{{Clarify|date=June 2011}} than it was for the same period of the previous year.{{cite news |title=As road toll jumps, police urge caution |date=10 June 2011 |work=The Sydney Morning Herald |publisher=Fairfax Media |url=http://www.smh.com.au/victoria/as-road-toll-jumps-police-urge-caution-20110610-1fvo8.html |access-date=14 June 2011}}

The Victoria government forecasts that a revenue of {{A$|245}} million will be raised from fines levied on drivers breaking Victorian road rules, a large proportion being from speed limit enforcement, in 2011.{{cite news |title=Speeding and disobedient drivers deliver a windfall for government coffers |date=11 June 2011 |work=Herald Sun|publisher=Herald and Weekly Times |url=http://www.heraldsun.com.au/news/more-news/road-rule-fines-deliver-61m-boost/story-fn7x8me2-1226073601195 |access-date=19 June 2011}}

Speed limit enforcement cameras were a substantial election issue in the provinces of Ontario and British Columbia, and were abolished by Premiers Mike Harris in 1995 and Gordon Campbell in 2001.

In February 2006, Edmonton, Alberta, erupted in scandal when it was alleged that two police officers accepted bribes from private contractors who received lucrative contracts to provide speed limit enforcement cameras. The officers and contractor involved now face criminal charges that remain before the courts.{{cite web |last=Edmonton |first=The |url=http://www.canada.com/edmontonjournal/news/cityplus/story.html?id=8329da53-62b8-4dc7-aae4-b9bdb1fdd4b4&k=42376 |title=Charges won't halt photo radar |publisher=Canada.com |date=19 February 2006 |access-date=24 May 2012 |archive-url=https://web.archive.org/web/20121108123030/http://www.canada.com/edmontonjournal/news/cityplus/story.html?id=8329da53-62b8-4dc7-aae4-b9bdb1fdd4b4&k=42376 |archive-date=8 November 2012 |url-status=dead }}

In September 2012, Edmonton police chief Rod Knecht proposed that "excessive speeders" should have their vehicles seized and impounded, after a rash of high speeding drivers were charged, many driving 50 – 100 km/h over the speed limit.{{cite news|last1=Wittmeier|first1=B|title=Police set sights on super speeders|url=http://www.canada.com/story.html?id=73f5ba54-47ab-4e33-97ac-5bfbad5b1469|newspaper=Edmonton Journal|access-date=3 June 2014|archive-url=https://web.archive.org/web/20140711092055/http://www.canada.com/story.html?id=73f5ba54-47ab-4e33-97ac-5bfbad5b1469|archive-date=11 July 2014|url-status=dead}}

{{Main|Road speed limit enforcement in the United Kingdom}}

The United Kingdom uses a variety of methods to enforce its road speed limits including average and instantaneous speed cameras; however, eight counties are to switch off or remove cameras and a further two counties are considering such action.{{cite news| url=https://www.bbc.co.uk/news/uk-england-10733021 |work=BBC News| title=Lack of police funds could end South West speed cameras | date=22 July 2010}}{{cite web |url=http://www.thisisgloucestershire.co.uk/news/Speed-cameras-stay-maintenance/article-2481320-detail/article.html |title=Speed cameras will stay – but no more maintenance | News |publisher=This is Gloucestershire |date=3 August 2010 |access-date=24 May 2012 |url-status=dead |archive-url=https://web.archive.org/web/20100806110145/http://www.thisisgloucestershire.co.uk/news/Speed-cameras-stay-maintenance/article-2481320-detail/article.html |archive-date=6 August 2010 }}{{cite news| url=http://news.bbc.co.uk/1/hi/england/wiltshire/8177247.stm |work=BBC News | title=Town ditches fixed speed cameras | date=31 July 2009}}{{cite news| url=https://www.telegraph.co.uk/motoring/news/7931842/Speed-camera-switch-off-sees-fewer-accidents.html | location=London | work=The Daily Telegraph| first=David | last=Barrett | title=Speed camera switch-off sees fewer accidents | date=7 August 2010}}

There has also been debate as to whether the use of such cameras in order to force a driver to confess to the crime of speeding is in violation of European basic human rights; however, in 2007 the European Court of Human Rights, in O’Halloran and Francis v United Kingdom, found there was no breach of article 6 of the Human Rights Act 1998 in requiring the keepers of cars caught speeding on camera to provide the name of the driver, or to be subject to criminal penalty of an equivalent degree of severity if they failed to do so.{{Cite web|url=https://hudoc.echr.coe.int/eng?i=001-81359|title=CASE OF O'HALLORAN AND FRANCIS v. THE UNITED KINGDOM|work=European Court of Human Rights|date=29 June 2007}}

The number of designated traffic officers fell from 15 to 20% of Police force strength in 1966 to seven percent of force strength in 1998, and between 1999 and 2004 by 21%.{{cite web|url=https://publications.parliament.uk/pa/cm200506/cmselect/cmtran/975/975.pdf|title=Section 21, traffic officer numbers reduction in the UK|work=UK Parliamentary publications}} It is an item of debate whether the reduction in traffic accidents per 100 million miles driven over this time{{cite web|url=http://www.dft.gov.uk/adobepdf/162469/221412/217792/4212241/transportstatisticgreatbrit.pdf|title=page 147 Transport statistics 2009 edition|work=Department for Transport UK}} has been due to robotic enforcement. In the seven-month period following speed cameras in Oxfordshire being switched off in August 2010, fatalities increased from 12 to 18, a figure not out of line with the variation in fatalities over a ten-year period.{{Cite news |url=https://www.theregister.co.uk/2011/04/01/oxfordshire_speed_cameras/ |title=Oxfordshire cops switch speed cameras back on |first=Jane |last=Fae |date=1 Apr 2011 |website=The Register }} Plans had been made to switch the cameras back on by November 2010, on the basis of increased speeds at camera sites,{{cite news| url=https://www.bbc.co.uk/news/uk-england-oxfordshire-11676603 |work=BBC News | title=Plan to return Oxfordshire's speed cameras | date=2 November 2010}} which occurred in April 2011.{{cite news| url=https://www.bbc.co.uk/news/uk-england-oxfordshire-13298715 |work=BBC News | title=Speeding fine numbers double with cameras back on | date=5 May 2011}} Oxfordshire had followed the lead of Swindon, which encountered a decline in casualties, serious injuries, and fatalities.

A 2017 Freedom of Information request found that 52% of speed cameras in the UK were switched on. The report showed that four out of the 45 police forces in the UK had no working speed cameras and that West Yorkshire, South Yorkshire, Greater Manchester, Kent and Cheshire police forces had a quarter or less active cameras. The report found that City of London, Metropolitan Police/TfL, Lancashire, Nottinghamshire, Suffolk and Northern Ireland police forces said that all of their cameras are active. The reason for this has been a cut in funding and many cameras, most notably many Gatso and Truvelo Combi speed cameras, still used older film technologies rather than newer digital technologies.{{Cite web|title=Half UK speed cameras are switched off|url=https://www.autoexpress.co.uk/car-news/consumer-news/101604/half-uk-speed-cameras-are-switched-off|access-date=2020-11-04|website=Auto Express|language=en}}{{Cite web|title=Half of Britain's speed cameras are switched off|url=https://news.sky.com/story/half-of-britains-speed-cameras-are-switched-off-11112323|access-date=2020-11-04|website=Sky News|language=en}}{{Cite news|date=2017-11-04|title=Half of UK road speed cameras are switched off|language=en-GB|work=BBC News|url=https://www.bbc.co.uk/news/uk-41869134|access-date=2020-11-04}}

{{See also|Speed limits in the United States}}

{{Update|date=May 2010}}

The NHTSA issued operational guidelines in 2008 for states and communities implementing speed camera programs.{{Cite web |date= |title=Speed Enforcement Camera Systems Operational Guidelines, DOT HS 810 916 |url=https://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa09028/resources/Speed%20Camera%20Guidelines.pdf |access-date=2025-05-04 |publisher=National Highway Traffic Safety Administration}}{{Cite web |title=Safety Impact of Speed and Red Light Cameras |url=https://www.congress.gov/crs-product/R46552 |access-date=2025-05-04 |website=www.congress.gov}} The guidelines cover such topics as planning, site selection, system procurement, public awareness, processing notices of violations, and evaluating the programs.

As of 2009, speed cameras existed in 48 communities in the United States, including in Arizona, Colorado, Illinois, Iowa, Louisiana, Maryland, Massachusetts, New Mexico, Ohio, Oregon, Tennessee, Washington, and Washington, D.C.{{cite news |date=4 June 2009 |title=Speed cameras on U.S. highways? |url=http://www.cnn.com/2009/LIVING/wayoflife/06/04/aa.speed.cameras.highways/index.html?eref=rss_tech |access-date=5 June 2009 |publisher=CNN}} {{As of|2020|August}}, this number increased to 152 communities.

In the U.S. state of Ohio, the issue of whether a city has jurisdiction under the Ohio Constitution to issue citations based on speed cameras was heard by the Ohio Supreme Court on 18 September 2007, in the case of Kelly Mendenhall et al. v. The City of Akron et al.{{cite web|url=http://www.newsnet5.com/news/10927743/detail.html |title=Woman's Lawsuit Threatens To Remove Red-Light Cameras|access-date=25 April 2010 |url-status=dead |archive-url=https://web.archive.org/web/20081216154334/http://www.newsnet5.com/news/10927743/detail.html |archive-date=16 December 2008 }}{{cite web |url=http://www.weathernet5.com/news/10957465/detail.html |archive-url=https://web.archive.org/web/20070928090606/http://www.weathernet5.com/news/10957465/detail.html |url-status=dead |archive-date=28 September 2007 |title=Lawsuit Over Red-Light Cameras Heads To Ohio Supreme Court |publisher=Weathernet5.com |access-date=24 May 2012 }} The court ruled in favor of Kelly Mendenhall.

Initially, Illinois used photo enforcement for construction zones only. There was legislation on the books to expand that throughout the state. However, Chicago has expanded its red light camera program and is planning to put speed cameras in school zones. Some suburbs (e.g. Alsip) already have cameras at various intersections.

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| footer = Two images from a speed enforcement camera in Mount Rainier, Maryland, documenting a vehicle alleged to be traveling 50 mph in a 25 mph zone

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Some U.S. states that formerly allowed red-light enforcement cameras but not speed limit enforcement cameras ('photo radar'), have now approved, or are considering, the implementation of speed limit enforcement cameras. The Maryland legislature approved such a program in January 2006. In 2005, 2006, 2008 and 2009 the California legislature considered, but did not pass, bills to implement speed limit enforcement cameras.{{cite web|url=http://www.highwayrobbery.net/redlightcamsjoin.htm#Action5 |title=Action/Legis – Red Light Cameras & Photo Radar in California |publisher=Highwayrobbery.net |access-date=24 May 2012}} Tennessee legislators are also considering expanding their speed limit enforcement cameras after successes in Chattanooga such as generating $158,811 in revenue in the first three months.{{cite web|last=Humphrey |first=Tom |url=http://www.knoxnews.com/news/2007/oct/30/speed-cameras-catch-police-chiefs-interest/ |title=Speed cameras catch police chief's interest » Knoxville News Sentinel |publisher=Knoxnews.com |access-date=24 May 2012}}{{cite news|url=http://www.chattanoogan.com/articles/article_116997.asp|title=City Red Light, Speeding Cameras Bring In $158,811 In First 3 Months|date=14 November 2007|publisher=The Chattanoogan.com|access-date=1 September 2008}}

A 2007 study of speed cameras on the Arizona State Route 101 in Scottsdale found a 50% reduction in the total crash frequency, with injuries falling by 40%; however, rear-end collisions increased by 55%.{{Cite web|url=http://www.scottsdaleaz.gov/Assets/documents/photoradar/WashingonRpt-101.pdf|archive-url=https://web.archive.org/web/20081204125802/http://www.scottsdaleaz.gov/Assets/documents/photoradar/WashingonRpt-101.pdf|url-status=dead|title=study of speed cameras|archive-date=4 December 2008}}

As of late 2008, cameras were placed along all Phoenix area freeways capturing drivers doing speeds greater than 11 mph over the posted speed limit. Over 100 new cameras were expected to be up and running by 2009.[http://www.abc15.com/content/news/phoenixmetro/story.aspx?content_id=c08f5be1-345f-4f76-923d-03f5f9ba19ce]{{dead link|date=May 2018|bot=InternetArchiveBot|fix-attempted=yes}}{{cite web|url=http://www.abc15.com/content/news/phoenixmetro/story.aspx?content_id=8f613b46-fc74-4b65-a4fe-d776fab6df88 |archive-url=https://archive.today/20081216151502/http://www.abc15.com/content/news/phoenixmetro/story.aspx?content_id=8f613b46-fc74-4b65-a4fe-d776fab6df88 |url-status=dead |archive-date=16 December 2008 |title=Drivers concerned about 100 new speed cameras in Valley |publisher=Archive.is |access-date=11 March 2019}}

In 2017, the National Safety Council graded states on road safety measures such as automated enforcement of speeding or red light cameras, interstate speed limits, and lower speed limits in school zones.{{Cite web|url=http://www.nsc.org/NSCDocuments_Advocacy/State-of-Safety/State-Report.pdf|title=National Safety Council (2017). The State of Safety - A State-by-State Report. Itasca, IL. pg. 18. Accessed at www.nsc.org}}

In the United States, it is common for all installation, operation, and verification procedures to be carried out by private companies that in some States receive payment based on the number of infringements they issue, and often under no testing regime whatsoever;[http://www.alexandrialawlibrary.com/red57927.dismiss-ord-080901.htm San Diego Court Ruling], 2001. however, these units are required by law to take at least two pictures of each vehicle.[http://safety.fhwa.dot.gov/intersections/rlrcam_tech.htm US Department Of Transportation Federal Highway Administration – Traffic Enforcement Camera Regulations] {{webarchive|url=https://web.archive.org/web/20090509064418/http://safety.fhwa.dot.gov/intersections/rlrcam_tech.htm |date=9 May 2009 }}, 9 December ^th 2008.

It has been announced that Arizona will not renew its contract with Redflex, the company that operates the cameras.{{cite web |title=No details yet for end to state's photo radar |url=http://ktar.com/?nid=6&sid=1291566 |access-date=24 May 2012 |publisher=KTAR.com}} However, many towns in Arizona (e.g. Chandler, Mesa, Scottsdale, Paradise Valley, Superior) still have red light and/or speed cameras. Photo enforcement is illegal in the town of Gilbert, Arizona. Tempe, Arizona has removed all of its red light cameras. Baker, Louisiana still contracts with Redflex.{{cite web |date=19 May 2008 |title=Redflex challenges private investigators ruling – The Independent Weekly |url=http://www.theind.com/index.php?option=com_content&task=view&id=2523&Itemid=94 |access-date=24 May 2012 |publisher=Theind.com}} This association is the subject of legislative action.[http://www.thenewspaper.com/rlc/docs/2009/la-hb480.pdf "HLS 09RS-632"] TheNewspaper.com. Retrieved 2024-07-21.

Opposition groups have formed in some locations where automated traffic enforcement has been used. In the US city of Scottsdale, Arizona, an activist group CameraFraud was formed and staged sign-wave protests and petition drives to oppose the use of speed limit enforcement cameras ('photo radar').{{cite web |url=http://www.myfoxphoenix.com/myfox/pages/Home/Detail;jsessionid=DE43213CB3C503CF8E9DC6239DACB7D0?contentId=7996744&version=2&locale=EN-US&layoutCode=VSTY&pageId=1.1.1&sflg=1 |title=MyFox Phoenix | Fox 10 News | KSAZ |access-date=25 April 2010 |url-status=dead |archive-url=https://web.archive.org/web/20090115204644/http://www.myfoxphoenix.com/myfox/pages/Home/Detail |archive-date=15 January 2009 }}[http://www.azfamily.com/video/localnews-index.html?nvid=322272&shu=1]{{dead link|date=May 2012}}{{cite web |url=http://www.abc15.com/content/news/phoenixmetro/story/Valley-activists-working-to-protest-photo-radar/CfKdulyJ0EGDqa7OXX2BuA.cspx |title=Valley activists working to protest photo radar cameras - Phoenix Arizona news, breaking news, local news, weather radar, traffic from ABC15 News | ABC15.com |access-date=25 April 2010 |url-status=dead |archive-url=https://web.archive.org/web/20090613000928/http://www.abc15.com/content/news/phoenixmetro/story/Valley-activists-working-to-protest-photo-radar/CfKdulyJ0EGDqa7OXX2BuA.cspx |archive-date=13 June 2009 }} In the 2008 elections in nearby Pinal County, Paul Babeau won an election for sheriff after making a campaign promise to eliminate speed cameras.[http://www.myfoxphoenix.com/myfox/pages/Home/Detail?contentId=8188969&version=1&locale=EN-US&layoutCode=VSTY&pageId=1.1.1]{{dead link|date=May 2012}}

{{As of|2020}}, eight states prohibit the use of automated enforcement.

{{urs|date=August 2023}}

Some jurisdictions in the United States have been found to fine motorists merely to generate revenue, rather than purely to assure safe driving, taking advantage of their unfamiliarity of the area or unwillingness to fight an out-of-town traffic ticket to assure them a constant stream of municipal funding. In the Southern United States, some towns have annexed thin strips of land far away from, and barely connected to, contiguous municipal limits to extend their authority along the highway to police stretches in isolated areas far away from any settlement or problem stretch of road which may justify a slower speed limit. In 2017 Damascus, Arkansas was investigated and prosecuted by state authorities for breaking state law by generating more than 30% of town revenue through traffic citations. In 2014, Waldo, Florida had its police department disbanded after the police were found to be issuing speeding tickets based on a quota system.

For decades, the American Automobile Association has published lists of 'speed trap towns' that motorists should avoid, to use an economic boycott to force towns to moderate their speed enforcement policies. These communities have had mixed results regarding campaigns against AAA to have their names removed from the list under the threat of economic ruin should motorists bypass those towns altogether. Many of the communities have also been successfully bypassed by states with divided highways rerouted to avoid these stretches of road after constituent complaints in addition to safety concerns.

Patagonia, Arizona, has been cited on the National Motorists Association's speedtrap.org website {{cite web |title=City |url=http://www.speedtrap.org/city/601/Patagonia |access-date=11 March 2019 |work=Speedtrap.org}} as having one of the nation's most active speed traps. City police regularly conceal their patrol cars behind trees along Arizona Highway 82 where motorists enter the city's outskirts. The legal speed limit drops in a short space from 55 mph to 30 mph, leading to some drivers who are not alert to be caught. The minimum fine for exceeding the posted speed limit even by 1 mph is $146.

In France, the fixed speed cameras on motorways are announced with a sign about half to 2 km before: Pour votre sécurité, contrôles automatiques (For your safety, automatic controls) and marked in French motorway maps.{{cite web|url=http://www.linternaute.com/auto/permis/radar/carte-radar.shtml |title=Carte des radars fixes et automatiques en France |publisher=Linternaute.com |access-date=24 May 2012}} On non-motorway roads, sometimes there is a sign; however, in other locations an electronic sign showing your speed may indicate a fixed speed camera further along the road. Average speed cameras now operate in some areas. It is forbidden there to use speed camera detectors.

In Switzerland, it is strictly forbidden to announce speed controls.{{cite web|url=http://www.20min.ch/news/schweiz/story/21702788 |title=Radarwarner: Bundesgericht kennt keine Gnade |date=17 December 2008 |publisher=20min.ch |access-date=24 May 2012}} If the software of navigation equipment includes the locations of fixed speed cameras, the devices can be seized and destroyed. This also applies to mobile phones or handheld devices with the appropriate function.

In Germany, radar detectors are prohibited; however, current mobile controls are mentioned by some radio stations, which is not illegal.{{Citation needed|date=April 2016}}

In Italy, the fixed speed cameras on motorways and highways are announced with a sign no less than 250 meters before (no less than 150 meters on urban roads and no less than 80 meters on the other roads): Controllo elettronico della velocità, and marked in Italian road maps.{{cite web|url=http://poliziadistato.it/articolo/175/ |title=Autovelox e Tutor: dove sono? |publisher=Poliziadistato.it |access-date=24 May 2012}}{{cite web |title=Multe nulle autovelox: quando le sanzioni vanno contestate |url=https://www.quotidianomotori.com/leggi-e-normative/autovelox-multa-nulla/ |website=Quotidiano Motori |access-date=24 Jun 2019}}

In the Netherlands, red light cameras are often combined with speed cameras in the same unit.{{Citation needed|date=April 2016}}

In Spain and Portugal, devices are used to detect drivers who drive too fast, and consequently traffic lights turn to red to stop the vehicle.[http://www.racfoundation.org/assets/rac_foundation/content/downloadables/speed_limits-box_bayliss-aug2012.pdf "Speed Limits A review of evidence"] RAC Foundation. Retrieved 2024-07-21.

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