Safety Impact of Speed and Red Light Cameras

September 28, 2020 R46552

Safety Impact of Speed and Red Light Cameras September 28, 2020
Traffic safety, defined as the rate of traffic-related deaths and injuries per mile driven, has greatly
improved in the United States over the past several decades. Yet, motor vehicle crashes remain
David Randall Peterman
one of the primary causes of premature death, and the leading cause of death for those under age
Analyst in Transportation
30, with around 37,000 people being killed each year and millions suffering injuries. These
Policy
crashes result in estimated overall costs of hundreds of billions of dollars each year. Speeding is a

contributing factor in over 9,000 deaths annually.

In-person enforcement is the most common form of speed enforcement in the United States. It
has several limitations; law enforcement officers are able to stop only a small proportion of speeders. Road design and traffic
conditions can make roadside stops difficult, and stops can be dangerous for both the driver and the law enforcement officer,
who are at risk from being struck by passing vehicles as well as from each other. Similarly, officers are rarely on the scene
when a motorist runs a red light. Automated traffic enforcement (ATE), such as cameras that capture images of vehicles that
are traveling above the speed limit or running stop lights, addresses several of the limitations of in-person speed and red light
enforcement: such systems can monitor thousands of cars an hour, are consistent and tireless, and do not put drivers or law
enforcement officers at risk during the ticketing process. They raise other issues: their use has been challenged on legal
grounds; some studies have found that while red light cameras reduce the number of right-angle crashes, they may increase
the number of rear-end collisions; and ATE systems often incite complaints that they are being used to raise revenue rather
than to promote safety. The National Highway Traffic Safety Administration (NHTSA) has recommended that ATE systems
be used to supplement, not replace, in-person speed enforcement.
Evidence from other countries, where ATE systems are widely used, suggests that ATE can be an effective means of
reducing the number of vehicle crashes and deaths and injuries without compromising mobility . In the United States,
adoption of ATE has been more limited; out of tens of thousands of local jurisdictions, approximately 150 communities are
currently using speed cameras and around 340 are using red light camera systems .
States and the federal government have acted to limit the use of ATE systems. Eight states prohibit speed cameras and red
light cameras, and another two dozen or so have no specific legislation to support the implementation of ATE. Of the states
that do have enabling legislation, many strictly limit the locations where such systems can be installed; often they are
permitted only in school zones, which are typically not problem spots for speed-related crashes. Congress has prohibited
states from using any of their federal transportation funding to fund ATE s ystems, except in school zones.
The Governors Highway Safety Association (GHSA) and the National Transportation Safety Board (NTSB) have called for
creation of a grant program to encourage states to address speeding. As Congress considers reauthorization of surface
transportation programs, it might address speeding; such a program could encourage the use of automated enforcement. Other
options for Congress include altering restrictions on use of federal funds for ATE, providing states with incentives to change
the legal status of ATE violations, and directing NHTSA to update its guidelines on automated speed enforcement, which
date to 2008.
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Safety Impact of Speed and Red Light Cameras

Introduction
Traffic safety, when defined as the rate of traffic-related deaths and injuries per mile driven, has
greatly improved in the United States over the past several decades. However, it remains the case
that motor vehicle crashes are one of the primary causes of death in the United States, with
around 37,000 people dying and mil ions suffering injuries each year;1 traffic crashes are the
leading cause of death of people under age 30.2 It is estimated that these crashes result in overal
costs of hundreds of bil ions of dollars each year.3
In 1990 the United States had one of the lowest rates of traffic deaths per mile in the world. Since
then, many other countries with auto-centric transportation systems have improved their highway
safety performance such that they now have lower traffic death rates than the United States.4
Evidence from other countries suggests that automated traffic enforcement (ATE), such as
cameras that record vehicles traveling above the speed limit or running stop lights, can be an
effective means of reducing vehicle crashes and deaths and injuries without compromising
mobility.5 ATE has not been adopted widely in the United States, and both states and Congress
have put limitations on its use.
This report examines the use of cameras to enforce traffic laws, and presents evidence about their
effectiveness. It raises a number of issues as Congress considers highway safety in the context of
reauthorization of federal surface transportation programs.
Speeding
Speeding, whether exceeding the posted speed limit or driving faster than is safe for the current
conditions, is one of the leading contributors to traffic crashes and the resulting deaths and
injuries. The National Highway Traffic Safety Administration (NHTSA) reports that speeding is a
contributing factor in roughly a quarter of traffic deaths each year; in 2018, 9,378 people died in
crashes in which at least one driver was speeding.6 Speeding-related crashes may be

1 In 2018, the most recent year for which data are available, 36,560 people were killed in motor vehicle crashes, down
from 37,473 in 2017. National Center for Statistics and Analysis, 2018 Fatal Motor Vehicle Crashes: Overview,
National Highway T raffic Safety Administration, T raffic Safety Facts Research Note, DOT HS 812 826, Washington,
DC, October 2019, at https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/812826.
2 Centers for Disease Control and Prevention, Winnable Battles: Motor Vehicle Injuries, at https://www.cdc.gov/
winnablebattles/report/motor.html.
3 T he calculation of the costs of motor vehicle crashes varies according to what types of costs are being counted. One
study estimated a cost of $242 billion in 2010 from lost productivity, medical costs, legal costs, property damage, and
time lost in congestion caused by crashes. When quality-of-life valuations were included, the estimated cost rose to
$836 billion. L. J. Blincoe, T . R. Miller, and E. Zaloshnja, et al., The Econom ic and Societal Im pact of Motor Vehicle
Crashes, 2010, National Highway T raffic Safety Administration, DOT HS 812 013, Washington, DC, May 2015, at
https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/812013. T he numbers of motor vehicle crashes, deaths, and
injuries were low in 2010 due to the effects of the 2007-2009 recession; applying the authors’ methodology to more
recent years would lead to higher cost estimates due to larger numbers of crashes and deaths.
4 International T raffic Safety Data and Analysis Group, Road Safety Annual Report 2019, International T ransport
Forum, OECD, Paris, France, October 7, 2019, T able 3, at https://www.itf-oecd.org/sites/default/files/docs/irtad-road-
safety-annual-report-2019.pdf.
5 Other speed-management efforts have included reducing speed limits in residential areas to 30 kilometers per hour
(18 miles per hour), adding traffic-calming features to help reduce speeds, and replacing intersections with
roundabouts.
6 National Highway T raffic Safety Administration, Traffic Safety Facts, 2018 Data: Speeding, DOT HS 812 932, April
2020, p. 1. At https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/812932. NHT SA refers to these as
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underreported: in an analysis of 2014 crash data involving a traffic-related fatality reported to
NHTSA, the National Transportation Safety Board (NTSB) found almost a thousand instances7 in
which vehicles that had been categorized as “not speeding” or “unknown if speeding” had been
traveling at least 10 miles per hour (mph) over the posted speed limit.8
Speeding is a doubly risky behavior: it both increases the risk of being involved in a crash and
increases the severity of a crash. Speeding limits a driver’s ability to steer safely around curves, to
avoid a dangerous situation, and to stop the vehicle in a short distance.
The relationship between speed and the risk of a crash is affected by many factors, including the
age of the driver, whether alcohol is involved, and the characteristics of the roadway (such as
width, curvature, and the presence of intersections). On the other hand, the relationship between
speed and the severity of injury in a crash is straightforward: the kinetic energy involved in a
crash increases exponential y as speed increases, and this is linked to greater risk of injury or
death. Higher crash speeds reduce the ability of the safety systems in the vehicle (seat belts,
airbags, crumple zones) and those around the roadway (guardrails and other barriers) to protect
vehicle occupants. The effect of higher speeds on pedestrians and cyclists involved in a motor
vehicle crash is especial y critical, due to their lack of protection: according to a 1995 European
Transport Safety Council study, a pedestrian struck by a vehicle travel ing 20 mph has a 95%
chance of survival, but a pedestrian struck at 45 mph has only a 15% chance of surviving.9
A periodic survey of speeding suggests that speeding is increasing in the United States: in free-
flow traffic conditions the percentage of vehicles exceeding the posted speed limit by 10 mph or
more rose from roughly 15% in 2007 to roughly 20% in 2015.10
The Location of Speed-Related Crashes
Speed-related crashes occur on roads of al types, with almost 10% of fatal speed-related crashes
on roads where the speed limit was 30 mph or less (see Figure 1).

“speeding-involved” fatalities, as there may have been other factors involved in the crash as well (e.g. , alcohol-
impairment).
7 Equal to 4% of the reported speeding-related fatalities that year.
8 National T ransportation Safety Board, Reducing Speed-Related Crashes Involving Passenger Vehicles, NT SB/SS-
17/01, July 25, 2017, p. 32, at https://www.ntsb.gov/safety/safety-studies/Documents/SS1701.pdf.
9 National T ransportation Safety Board, Reducing Speed-Related Crashes Involving Passenger Vehicles, NT SB/SS-
17/01, July 25, 2017, p. 27, at https://www.ntsb.gov/safety/safety-studies/Documents/SS1701.pdf.
10 T his was true for interstates and other freeways, major arterial roads, and minor arterial and collector roads. R. Huey,
D. De Leonardis, and M. Freedman, National Traffic Speeds Survey: 2007, National Highway T raffic Safety
Administration, DOT HS 811 663, Washington, DC, August 2012, at https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/
811663.pdf; D. De Leonardis, R. Huey, and J. Green, National Traffic Speeds Survey III: 2015, National Highway
T raffic Safety Administration, DOT HS 812 485, Washington, DC, March 2018, at https://www.nhtsa.gov/sites/
nhtsa.dot.gov/files/documents/812485_national-traffic-speeds-survey-iii-2015.pdf.
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Safety Impact of Speed and Red Light Cameras

Figure 1. Vehicles in Fatal Crashes by Speed Limit, 2017
Percent of al vehicles involved in fatal crashes

Source: CRS, based on data from NHTSA, Traffic Safety Facts 2017, Table 33.
Note: Includes each vehicle in multivehicle crashes.
Links Between Speeding and Other Risky Behaviors
Not al drivers are equal y likely to be involved in speed-related fatal crashes. Young male drivers
are much more likely to be involved in such crashes than are female drivers or older drivers.11
Drivers involved in such crashes are also more likely, in the five years before the fatal crash, to
have been involved in other crashes, to have had their driver’s licenses suspended or revoked,12 or
to have been cited for speeding or driving while intoxicated, compared to drivers involved in fatal
crashes who were not speeding.13 Alcohol use is closely linked to involvement in speed-related
fatal crashes: 42% of drivers involved in speed-related crashes had some alcohol in their system,
while 19% of drivers in fatal crashes not involving speeding had some alcohol in their system.14
Studies indicate that alcohol both impairs driver skil and increases risky driving behaviors,
including speeding and following too close.15

11 National Highway T raffic Safety Administration, Traffic Safety Facts, 2018 Data: Speeding, DOT HS 812 932, April
2020, Figure 1, at https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/812932.
12 Among speeding drivers involved in fatal crashes in 2018, 25% did not have a valid driver’s license at the time of the
crash. National Highway T raffic Safety Administration, Traffic Safety Facts, 2018 Data: Speeding , DOT HS 812 932,
April 2020, p. 1, at https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/812932.
13 Ibid., Figure 2.
14 Ibid., T able 3.
15 Jennifer R. Laude and Mark T . Fillmore, “Simulated Driving Performance Under Alcohol: Effects on Driver -Risk
Versus Driver-Skill,” Drug Alcohol Dependency, Vol 154 (September 1, 2015), pp 271 -277, at
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4536118/.
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Drivers have a paradoxical view of speeding: most drivers regard speeding as dangerous, but
most drivers also admit to speeding.16 Like many other risky driving behaviors, speeding
increases the risk of a crash but usual y does not result in a crash. While drivers may say speeding
is dangerous, in practice they may not perceive speeding as being particularly risky. Thus
speeding is formal y criticized, but is a social y accepted behavior.17 Roadway design has
improved over time, which may contribute to speeding by making drivers feel safe driving at
higher speeds. A speeding driver can influence the driving behavior of others; seeing someone
speed by one’s vehicle can make it more likely that one wil adopt that behavior.18
Deterring Speeding
Speed enforcement general y aims to deter speeding. Deterrence in this context has multiple
components. It involves enacting laws that prohibit speeding, publicizing and enforcing those
laws, and punishing offenders. Drivers may assume that law enforcement wil tolerate speeds
slightly over the posted limit. If drivers believe that they are likely to be detected and fined or
arrested for exceeding that margin, most wil limit their speed accordingly.19
Conceptual y, deterrence is typical y divided into three components: the swiftness of the
punishment, the certainty of the punishment, and the severity of the punishment. Research
indicates that the certainty of being caught is vastly more important than is the severity of the
punishment in affecting behavior.20 In-person speed enforcement—a police officer pulling over a
speeding driver or a driver who has just run a red light—may be swift, but the likelihood of being
caught is low: no officer may be nearby, traffic enforcement is typical y only one among many
responsibilities for an officer, and, given the time required to write the ticket for an offending
driver, an officer can deal with only a handful of offenders in the course of an hour.
Using roadside stops by law enforcement officers to deter speeding may raise other concerns.
Pulling a driver over to issue a citation for speeding may increase congestion and pose a safety
hazard, and in some locations a driver may be unable to stop out of the flow of traffic. Roadside
stops can be dangerous, due both to the risk that other vehicles wil hit law enforcement

16 In a 2019 survey, 87% of drivers considered it unacceptable to drive 10 mph over the speed limit on a residential
street, yet 42% reported having done so in the previous 30 days. AAA Foundation for T raffic Safety, 2019 Traffic
Safety Culture Index, June 2020, p. 17, https://aaafoundation.org/wp-content/uploads/2020/06/2019-Traffic-Safety-
Culture-Index.pdf.
17 T his is true not only in the United St ates (e.g., L.J. Mountain, W.M. Hirst, and M.J. Maher, “Costing Lives Or
Saving Lives: A Detailed Evaluation of the Impact of Speed Cameras,” Traffic Engineering and Control, vol. 45, no. 8
(2004), pp. 280-287), but also in many other countries (e.g., David Soole, Barry Watson, and Judy Fleiter, “ A Review
of International Speed Enforcement Policies and Practices: Evidence-based Recommendations for Best Practice,” In S.
Landry, N. Stanton, A. Vallicelli, and G. Di Bucchianico, Advances in Hum an Aspects of Transportation, Part I:
Proceedings of the 5th International Conference on Applied Hum an Factors and Ergonom ics, AHFE 2014, pp. 553-
566, https://eprints.qut.edu.au/75877/.
18 Judy J. Fleiter, Alexia Lennon, and Barry Watson, “How Do Other People Influence Your Driving Speed? Exploring
the ‘Who’ and the ‘How’ of Social Influences on Speeding From a Qualitative Perspective,” Transportation Research
Part F: Traffic Psychology and Behaviour, vol. 13, issue 1, January 2010, pp. 49-62, at https://doi.org/10.1016/
j.trf.2009.10.002.
19 Jeremy D. Davey and James E. Freeman, “Improving Road Safety T hrough Deterrence -Based Initiatives: A Review
of Research,” Sultan Qaboos University Medical Journal, vol. 11(1), February 2011, pp. 29-37, at
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3074684/.
20 Daniel S. Nagin, “Deterrence in the T wenty-First Century,” in Crime and Justice in America, ed. M. T onry, Chicago,
Ill: University of Chicago Press, 199-264, cited in “ Five T hings About Deterrence,” National Institute of Justice, U.S.
Department of Justice, June 5, 2016, https://nij.ojp.gov/topics/articles/five-things-about-deterrence#note1.
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Safety Impact of Speed and Red Light Cameras

officers,21 stopped drivers, passengers, or their vehicles and the potential for the interaction
between the law enforcement officer and driver or passenger to lead to violence during traffic
stops.
Traffic stops can be problematic in other ways. The discretion that law enforcement officers
employ in deciding whether or not to stop a vehicle that is speeding, to search a vehicle when
stopped, and to issue a citation or even arrest the driver raises constitutional questions about
abuse of civil rights and bias in enforcement.22 In the exercise of that discretion, some studies
suggest minorities are pulled over and ticketed at higher rates than other groups.23
Enforcement of speed limits can influence driving behavior through two means: specific
deterrence (the impact of legal penalties on offenders) and general deterrence (the impact of the
threat of detection and penalties on the general driving public). Studies have found that when
speed enforcement is focused on a particular location, speeding is reduced at that location. Some
studies have found that the reduction in speeding is confined to that location; other studies have
found a “halo” effect, with speeds declining in the area around the speed camera location.24
Another approach to general deterrence is the use of mobile speed cameras; when speed
enforcement efforts are regularly moved from one location to another, drivers may feel that speed
enforcement can happen anywhere at any time and adhere more closely to the speed limit
wherever they are driving.25 A third approach to general deterrence is the use of point-to-point
(average speed) cameras, which measure a driver’s average speed over a distance up to several
miles. Studies of average speed camera programs have found large reductions in average speed,
speed variability, fatal and serious injury crash rates, and reductions in journey times (due to the
reduction in crash-induced congestion and in the accordion effect of braking).26

21 Over the period 2009-2018, an average of a dozen law enforcement officers a year died after being struck by a
vehicle: National Law Enforcement Officers Memorial Fund, Causes of Law Enforcem ent Deaths Over the Past
Decade (2009-2018), at https://nleomf.org/facts-figures/causes-of-law-enforcement -deaths.
22 Illya Licthenberg, “ Police Discretion and T raffic Enforcement: A Government of Men ,” Cleveland State Law
Review, vol. 50, issue 3 (2003), p. 425, at https://engagedscholarship.csuohio.edu/clevstlrev/vol50/iss3/4/.
23 T om Abate, “Black Drivers Get Pulled Over by Police Less at Night When T heir Race is Obscured by ‘Veil of
Darkness,’ Stanford Study Finds,” Stanford News, May 5, 2020, at https://news.stanford.edu/2020/05/05/veil-darkness-
reduces-racial-bias-traffic-stops/; Wendy C. Regoeczi and Stephanie Kent, “ Race, Poverty, and the T raffic T icke t
Cycle: Exploring the Situational Context of the Application of Police Discretion,” Policing, vol. 37, no. 1 (2014), pp.
190-205. However, the conclusions of such measures are subject to question, as “ there is no clear way to establish the
correct populat ion at risk for police attention,” Greg Ridgeway and John McDonald, Methods for Assessing Racially
Biased Policing, RAND Corporation, 2010, p. 27, at https://www.rand.org/content/dam/rand/pubs/reprints/2011/
RAND_RP1427.pdf.
24 T his “halo” effect has also been noted with in-person speed enforcement efforts; European Commission, Mobility
and Transport: Road Safety, “ T ime and Distance Halo Effects,” at https://ec.europa.eu/transport/road_safety/specialist/
knowledge/speed_enforcement/additional_considerations_on_speed_enforcement/time_and_distance_halo_effects_en.
25 David Soole, Barry Watson, and Judy Fleiter, “ A Review of International Speed Enforcement Policies and Practices:
Evidence-based Recommendations for Best Practice,” pp. 7 & 9, Proceedings of the 5th International Conference on
Applied Hum an Factors and Ergonom ics AHFE 2014, edited by T . Abram, W. Karwowski and T . Marek, Krakow,
Poland, July 19-23, 2014, pp. 5-6, at https://eprints.qut.edu.au/75877/18/75877.pdf.
26 T he accordion effect refers to the impact of decelerations and accelerations by a driver in response to the vehicle
ahead, which increase in impact as the number of drivers reacting increases. For example , a driver going 60 mph
encounters a vehicle going 55 mph and for some reason cannot immediately pass it, so brakes to slow to 55 mph; if
another driver is close behind, that driver will also brake, perhaps slightly harder in reaction to the brake lights o f the
vehicle that had been going 60 mph, and so forth, producing a “ backward traveling wave” that can last for miles. T his
effect can cause a lane of traffic to come to a complete stop, sometimes referred to as a phantom traffic jam. “T raffic
Jam Mystery Solved by Mathematicians,” Phys.org, December 19, 2007, at https://phys.org/news/2007-12-traffic-
mystery-mathematicians.html.
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Red Light Running
Red light violations involve a driver entering and proceeding through a signalized intersection
after the traffic signal has turned red. Drivers turning right on red without coming to a stop before
turning or turning right on red where that action is prohibited also are considered red light
violations.
As with speeding, most instances of running a red light do not result in a crash. However, crashes
resulting from red light violations can be particularly severe,27 as they often result in right-angle
(“T-bone”) collisions in which the force of the vehicle running the red light strikes a crossing
vehicle in the side. Modern cars typical y have sophisticated engineering features to protect
occupants in the event of front- and rear-impact crashes. The length of the vehicle body in front
of and behind the passenger compartment al ows for crumple zones to absorb the energy of the
crash and for seat belts and airbags to protect the occupants from the forces of impact. In side-
impact crashes, the initial impact may be directly into the passenger compartment, where there is
little space or material to absorb the energy of the striking vehicle before it reaches the vehicle
occupant, and at an angle where seat belt and side-impact airbags offer comparatively less
protection for occupants.
In 2018, 846 people were kil ed, and an estimated 139,000 people were injured in crashes that
involved running of red lights.28 Many of those kil ed and injured were pedestrians and cyclists.
According to the Insurance Institute for Highway Safety, drivers involved in fatal red light
running crashes that involved multiple vehicles are more likely to be young males, to have prior
crashes or convictions for driving while intoxicated, and to be driving without a valid license at
the time of the crash.29 They are also more likely to be speeding or intoxicated at the time of the
red light running crash.
The chal enges of preventing red light running are similar to some of the chal enges to preventing
speeding. Red light running has a degree of social acceptability: most drivers condemn running of
red lights, while many drivers also admit to doing so.30
In-person enforcement of red light running has issues similar to those of in-person enforcement of
speed limits. Police resources are limited relative even to the number of red lights where red light
violations may commonly occur. Chasing down a motorist who has run a red light may be
dangerous, road conditions may make a roadside stop dangerous, and a roadside stop may
exacerbate traffic congestion, particularly during rush-hour traffic conditions.

27 Making Intersections Safer: A Toolbox of Engineering Countermeasures to Reduce Red-Light Running, Institute of
T ransportation Engineers and Federal Highway Administration, 2003, pp. 6 -7, at https://safety.fhwa.dot.gov/
intersection/conventional/signalized/rlr/rlr_toolbox/rlrbook.pdf.
28 Insurance Institute for Highway Safety, Red Light Running, “By the Numbers,” at https://www.iihs.org/topics/red-
light-running#by-the-numbers.
29 Ibid.
30 Eighty-six percent of drivers surveyed reported running a red light to be very or extremely dangerous, yet 31%
reported doing so within the previous 30 days. AAA Foundation for T raffic Safety, 2019 Traffic Safety Culture Index,
June 2020, T ables A5 & A7, at https://aaafoundation.org/wp-content/uploads/2020/06/2019-Traffic-Safety-Culture-
Index.pdf.
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Automated Enforcement
ATE uses cameras to identify a vehicle that exceeds the posted speed limit (typical y by some
specified margin) or has violated a red traffic signal and to take a photo of the vehicle (and, in
some cases, the driver). Law enforcement and ATE vendor personnel then review the photo to
identify whether it has recorded a speeding or red light violation. State motor vehicle records are
used to determine where to mail the citation. The photo is used to generate a citation that is
mailed to either the owner of the vehicle or, in some states, the driver of the vehicle (identified
from the photo).
Rather than directly own speed cameras or red light cameras, local or state authorities normal y
contract with private companies that provide the equipment and help to operate it.31
In some states, speeding and red light running violations are treated like parking tickets; the
vehicle owner is fined, but no criminal charges are brought, no “points” are assessed to the
driver’s license, and the violations are not reported to insurance companies. The penalties are not
assessed to the driver of the vehicle, but to the owner. In other states, these violations are treated
like moving traffic violations, with the systems required to provide evidence to identify the driver,
and penalties including license sanctions may be levied against the driver, rather than the owner,
of the vehicle. In one form or another, ATE is employed in approximately half the states (Figure
2).
Figure 2. States Where Speed or Red Light Cameras Are in Use, 2020

Source: Insurance Institute for Highway Safety.

31 National Highway T raffic Safety Administration, Speed Enforcement Program Guidelines, DOT HS 810 915, March
2008, p. 18, at https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/810915.pdf; R. J. Miller, J. S. Osberg, R. Retting, et al.,
System Analysis of Autom ated Speed Enforcem ent Im plementation , National Highway T raffic Safety Administration,
DOT HS 812 257, April 2016, p. 50, at https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/812257_systemanalysisase.pdf.
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Automated Speed Enforcement
Automated speed enforcement combines a vehicle speed detection system with a camera to
identify and photograph speeding vehicles. There are a variety of speed camera systems: cameras
can be fixed (i.e., placed in one spot and left there, typical y at a location chosen due to a
relatively high number of speed-related crashes) or mobile (placed in a vehicle that can be driven
to a location and parked for a period of time, then driven to another location; these vehicles can
be marked or unmarked).
A third type of speed camera system, used in other countries but not in the United States, is the
average speed camera system (sometimes cal ed a point-to-point camera system). This type of
speed camera addresses a criticism of fixed speed cameras: that drivers who know the location of
the cameras slow down at those locations but speed before and after passing the cameras. Average
speed cameras are mounted in pairs at a distance (ranging from hundreds of yards to several
miles), take a time-stamped photo of each vehicle, use license plate readers to check the time each
vehicle took to travel from the first location to the second, and issue tickets when a vehicle’s
average speed over the distance is above the limit.32
There have been many studies of speed camera programs; most have concluded that speed
cameras reduced speeding and/or crashes in the vicinity of the cameras, and in some cases in the
surrounding areas. Several reviews that looked at dozens of studies from around the world found
that despite methodological issues in most studies, speed cameras reduce speeding and/or
crashes.33 In its evidence-based guide to traffic safety measures, NHTSA gives ATE (including
both speed cameras and red light cameras) the highest rating for effectiveness;34 the setting of
speed limits themselves is the only other countermeasure rated as demonstrated to be effective in
limiting speeding.35 Similarly, automated speed enforcement is the only speeding-related
countermeasure included by the Centers for Disease Control and Prevention in its tool to enable
states to model cost-effective interventions to reduce traffic deaths and injuries.36 The NTSB also
considers automated speed enforcement to be “an effective countermeasure to reduce speeding-
related crashes, fatalities, and injuries.”37

32 Jenoptik, Average Speed Cameras, at https://www.jenoptik.us/products/road-safety/average-speed-camera.
33 Lawrence E. Decina, Libby T homas, and Raghavan Srinivasan , et al., Automated Enforcement: A Compendium of
Worldwide Evaluations of Results, National Highway T raffic Safety Administration, DOT HS 810 763, Washington,
DC, September 2007, at https://www.nhtsa.gov/DOT /NHT SA/T raffic%20Injury%20Control/Articles/
Associated%20Files/HS810763.pdf; Cecilia Wilson, Charlene Willis, and Joan K. Hendrikz, et al., “ Speed Cameras for
the Prevention of Road T raffic Injuries and Deaths,” Cochrane Database of System atic Reviews 2010 , Issue 11,
https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD004607.pub4/full; Daniel J. Graham, Cian Naik,
Emma J. McCoy, “Do Speed Cameras Reduce Road T raffic Collisions?,” PLOS One, September 16, 2019, at
https://doi.org/10.1371/journal.pone.0221267.
34 Automated enforcement receives five stars for effectiveness, denoting measures that have been “Demonstrated to be
effective by several high-quality evaluations with consistent results.” C. M. Richard, K. Magee, and P. Bacon -
Abdelmoteleb, et al., Counterm easures That Work: A Highway Safety Counterm easure Guide for State Highway Safety
Offices, Ninth Edition, National Highway T raffic Safety Administration, DOT HS 812 478, Washington, DC, April
2018, pp. 3-20–3-26, at https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/812478_countermeasures-that-
work-a-highway-safety-countermeasures-guide-.pdf.
35 T he other measures considered are Aggressive Driving and Other Laws; High-Visibility Enforcement; Other
Enforcement Methods; Penalty T ypes and Levels; Diversion and Plea Agreement Restrictions, T raffic Violator School;
and Communications and Outreach Supporting Enforcement . Ibid.
36 The Motor Vehicle Prioritizing Interventions and Cost Calculator for States (MV PICCS) , at https://mvpiccs-
viz.cdc.gov:8008/.
37 National T ransportation Safety Board, Reducing Speed-Related Crashes Involving Passenger Vehicles, NT SB/SS-
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Use of Speed Cameras in Other Countries
A number of countries have made extensive use of speed cameras in their highway safety
programs.38 In France, use of automated enforcement was a key feature of a highway safety
initiative announced in 2002, and was credited with reductions in both average speeds and fatal
crashes.39 Australia introduced such cameras in 1985, and as of 2014 mobile speed cameras were
“arguably the most common method of enforcing speed limits.”40 The percentage of light vehicles
in free-flowing traffic exceeding the speed limit by more than 10 kilometers per hour (roughly 6
mph) dropped from 36% in 2001 to 10% in 2009.41 The United Kingdom introduced speed
cameras and other speed-calming measures in 1990. A comparison of fatal crashes over the
ensuing decade in the U.K. and the United States (where speed cameras were introduced in a
limited and sporadic fashion) found that U.K. road deaths dropped by 34% from 1990-1999,
compared to a 6.5% drop in the United States. The study suggested the greater reduction in fatal
crashes in the U.K. was due largely to smal decreases in the speed of drivers due to the
introduction of speed cameras and other speed-calming measures.42
Speed Camera Usage in the United States
Of the tens of thousands of local governments in the United States, 152 communities had speed
camera programs in place as of August 2020.43 Eight states prohibit the use of automated
enforcement, 19 states explicitly permit it, and 23 states do not have legislation addressing
automated enforcement.
Listing the states that permit speed cameras can give a misleading impression of the extent of
their usage, since systems typical y operate in specific communities rather than statewide. For
example, New Mexico has speed cameras in one smal community,44 and New York has speed
cameras in two communities (one of these is New York City, which includes 45% of the state’s
population). Both states limit the cameras to school zones.45 In Maryland, where 41 jurisdictions

17/01, July 25, 2017, p. 37, at https://www.ntsb.gov/safety/safety-studies/Documents/SS1701.pdf.
38 David Soole, Barry Wat son, and Judy Fleiter, “ A Review of International Speed Enforcement Policies and Practices:
Evidence-based Recommendations for Best Practice,” Proceedings of the 5th International Conference on Applied
Hum an Factors and Ergonom ics AHFE 2014, edited by T . Abram, W. Karwowski, and T . Marek, Krakow, Poland,
July 19-23, 2014, at https://eprints.qut.edu.au/75877/18/75877.pdf.
39 Laurent Carnis and Etienne Blais, “ An Assessment of the Safety Effects of the French Speed Camera Program,”
Accident Analysis and Prevention, 51 (2013) 301-309.
40 David Soole, Barry Watson, and Judy Fleiter, op cit., p. 2.
41 T ransportation Research Board, Achieving Traffic Safety Goals in the United States: Lessons from Other Nations,
Special Report 300, Washington, DC, 2011, pp. 77, 81.
42 Elihu Richter, Lee S. Friedman, T amar Berman, Avrahim Rivkind, “Death and Injury from Motor Vehicle Crashes:
A T ale of T wo Countries,” American Journal of Preventive Medicine, vol. 29, no. 5, 2005, pp. 440-449.
43 Insurance Institute for Highway Safety, personal communication, August 26, 2020.
44 New Mexico Department of T ransportation, Biennial Survey of State Automated Traffic Enforcement Systems, 2020,
at https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/new_mexico_ae2020_survey.pdf.
45 New York State, Automated Traffic Enforcement System Biennial Survey [FY2020], at https://www.nhtsa.gov/sites/
nhtsa.dot.gov/files/documents/new_york_ae2020_survey.pdf.
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use speed cameras,46 state law limits their placement to work zones on roads with speed limits of
45 mph or more and to school zones, with a few other al owances in specific jurisdictions.47
The first sustained automated speed enforcement program in the United States was implemented
in Paradise Val ey, AZ, in 1987.48 Adoption of speed cameras was relatively slow, with some
communities adopting and later canceling automated speed enforcement programs. This pattern
changed in the mid-2000s, when the number of communities adopting automated speed
enforcement grew from around 20 in 2005 to over 140 in 2013 before plateauing (see Figure 3).
Figure 3. Trend in Communities Using Automated Speed Enforcement

Source: CRS, based on data from the Insurance Institute of Highway Safety.
Note: The numbers in the chart are net numbers for each year; the total number of communities that have used
such systems is somewhat larger, as some communities have adopted and subsequently terminated their systems.
Red bars represent years of notable policy changes: the 2004 American Association of State Highway and
Transportation Officials resolution supporting greater use of automated speed enforcement, and the 2012
congressional limitation on use of ATE.
Although speed camera programs are typical y adopted at the community level, both federal and
state actions appear to play a role in the use of automated speed enforcement. Congress gave the
federal Department of Transportation (DOT) the discretion to promote the use of ATE in 1991.
However, usage of camera systems stayed relatively low until after the American Association of
State Highway and Transportation Officials (AASHTO, the association of state departments of
transportation and transit agencies) adopted a resolution cal ing on states to support greater use of

46 Seventeen jurisdictions have both speed and red light cameras, 24 have only speed cameras, and 5 have only red light
cameras. University of Maryland Center for Advanced T ransportation T echnology, Automated Enforcement Survey
Report, T able 2, Maryland Department of T ransportation, Motor Vehicle Administration, Highway Sa fety Office,
February 27, 2020, at https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/maryland_ae2020_survey.pdf.
47 University of Maryland Cent er for Advanced T ransportation T echnology, Automated Enforcement Survey Report,
Maryland Department of T ransportation, Motor Vehicle Administration, Highway Safety Office, February 27, 2020, at
https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/maryland_ae2020_survey.pdf.
48 National Highway T raffic Safety Administration, Speed Enforcement Camera Systems Operational Guidelines, DOT
HS 810 916, March 2008, p. 5, at https://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa09028/resources/
Speed%20Camera%20Guidelines.pdf.
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automated speed enforcement in 2004.49 The Governors Highway Safety Association (GHSA)
issued a similar cal the following year, asking Congress to create a grant program to encourage
the use of automated speed enforcement. In 2007 the International Association of Chiefs of Police
passed a resolution encouraging the use of speed cameras in locations with high rates of crashes,
in conjunction with in-person traffic enforcement.50
Some surveys of communities where automated speed enforcement programs were implemented
have found that support for automated speed enforcement increased after implementation.51
However, an ongoing survey by the AAA Foundation for Traffic Safety suggests that public
support for speed cameras has been waning. In 2008, 68% of respondents “somewhat” or
“strongly” supported using automated speed enforcement on neighborhood streets, with 18%
“somewhat” or “strongly” opposed; in 2018, 42% of respondents “somewhat” or “strongly”
supported using cameras to ticket cars going 10 mph over the speed limit on residential streets,
and 53% “somewhat” or “strongly” opposed such a law.52
One possible reason for increased public opposition to speed cameras is that they appear to result
in a greater number of citations than in-person stops. In 2015, an estimated 7.9 mil ion U.S.
drivers were stopped by police for speeding, not al of whom received speeding tickets. In 2017,
more than 2.2 mil ion speed camera tickets were issued in the Washington, DC, metropolitan area
alone.53 While these numbers are not directly comparable, they indicate that automated
enforcement may be associated with a much greater number of citations per mil ion licensed
drivers.
After al owing the Secretary of Transportation to encourage states to adopt speed cameras in
1991, in 2012 Congress prohibited states from using federal transportation funding to purchase,
operate, or maintain ATE systems except in certain circumstances.54 The number of communities
using speed cameras has grown slightly since 2012.

49 T ransportation Research Board, Automated Enforcement for Speeding and Red Light Running , National Cooperative
Highway Research Program Report 729, Washington, DC, 2012, p. 3, at https://safety.fhwa.dot.gov/speedmgt/
ref_mats/fhwasa1304/resources2/27%20-
%20Automated%20Enforcement%20for%20Speeding%20and%20Red%20Light%20Running.pdf .
50 Ibid.
51 E.g., Jessica B. Cicchino, Joann K. Wells, and Anne T . McCartt, “Survey About Pedestrian Safety and Attitudes
T oward Automated T raffic Enforcement in Washington, DC,” Traffic Injury Prevention, vol. 15, no. 4 (2014), pp. 414-
423, and Richard A. Retting, Sergey Y. Kyrychenko, and Anne T . McCartt, 2008. “Evaluation of Automated Speed
Enforcement on Loop 101 Freeway in Scottsdale, Arizona,” Accident Analysis & Prevention vol. 40, no. 4 (2008), pp.
1506-1512, cited in National T ransportation Safety Board, Reducing Speeding-Related Crashes Involving Passenger
Vehicles, Safety Study NT SB/SS-17/01, July 25, 2017, p. 39, at https://www.ntsb.gov/safety/safety-studies/Documents/
SS1701.pdf.
52 Since the question had become more specific about the policy in 2018 compared to 2008, it is possible that the
change in wording affected the levels of support and opposition expressed. AAA Foundation for T raffic Safety, 2008
Traffic Safety Culture Index, T able 20, April 2008, at https://aaafoundation.org/wp-content/uploads/2018/02/
2008T SCIndexReport.pdf; 2018 Traffic Safety Culture Index, T able 6, June 2019, at https://aaafoundation.org/wp-
content/uploads/2019/06/2018-TSCI-FINAL-061819_updated.pdf.
53 Elizabeth Davis, Anthony Whyde, and Lynn Langton, Bureau of Justice Statistics Special Report: Contacts Between
Police and the Public, 2015, Office of Justice Programs, U.S. Department of Justice, NCJ 251145, October 2018, Table
5 (number of drivers in traffic stops) and T able 10 (reasons for t raffic stops), at https://www.bjs.gov/content/pub/pdf/
cpp15.pdf; Luz Lazo, “ Drivers continue to ignore speed cameras in the District, earning city more than $100 million ,”
Washington Post, September 26, 2018, at https://www.washingtonpost.com/transportation/2018/09/26/drivers-
continue-ignore-speed-cameras-district-earning-city-more-than-million.
54 In T he Moving Ahead for Progress in the 21st Century Act (P.L. 112-141), Section 1533 prohibited states from using
any of their federal Highway Safety Improvement Program funds, which are distributed by the Federal Highway
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NHTSA Guidelines for Speed Camera Systems
NHTSA issued operational guidelines in 2008 for states and communities implementing speed
camera programs.55 The guidelines cover such topics as planning, site selection, system
procurement, public awareness, processing notices of violations, and evaluating the programs.
A later survey of communities with speed camera programs found that 63% of program
administrators were not aware of the NHTSA operational guidelines, though most programs were
consistent with the guidelines in many areas.56 The survey found that among the NHTSA
guidelines that communities most frequently failed to follow were the following:
 Automated speed enforcement programs should use a combination of fines and
license sanctions as penalties and should provide photographic evidence to
identify the driver of the vehicle. Some 23% of respondents used both fines and
sanctions to penalize violators, and 32% used photos to identify drivers.57
 During the planning process for implementing an automated speed enforcement
program, an advisory panel of stakeholder representatives should guide the
program development and provide input. Some 27% of respondents reported the
existence of such an advisory panel.58
In a 2017 report, the NTSB noted that DOT’s 2008 speed camera program guidelines did not
reflect more recent changes in technology and operations, such as the use of point-to-point speed
enforcement. It recommended that the Federal Highway Administration and NHTSA update the
guidelines and promote their use.59
Red Light Camera Programs
In numerous studies, red light cameras have been shown to decrease the number of both red light
violations and crashes involving injuries and fatalities at signalized intersections.60 There is some

Administration, to purchase, operate, or maintain an AT E system, except in school zones, and Section 31102(c)
prohibited states from using any of their federal Highway Safety Formula Program funds, which are distributed by
NHT SA, to purchase, operate, or maintain an AT E system, with no exceptions.
55 National Highway T raffic Safety Administration, Speed Enforcement Camera Systems Operational Guidelines, DOT
HS 810 916, March 2008, at https://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa09028/resources/
Speed%20Camera%20Guidelines.pdf.
56 R. J. Miller, J. S. Osberg, R. Retting, et al., System Analysis of Automated Speed Enforcement Implementation ,
National Highway T raffic Safety Administration, DOT HS 81 2 257, April 2016, p. 99-100, at https://www.nhtsa.gov/
sites/nhtsa.dot.gov/files/812257_systemanalysisase.pdf.
57 T here is evidence that monetary fines assessed against the vehicle owner can be effective in deterring speeding, but
“this approach helps feed ASE criticism that these programs are created for the mere purpose of collecting fines and do
not serve legitimate traffic safety goals.” Ibid, pp. 99-100. Several states provide that penalties shall be assessed against
the vehicle and not the driver; in such states there is no need for communities to have automated speed enforcement
technology that identifies the driver.
58 T he survey notes that given the often contentious nature of automated speed enforcement programs, incorporating
stakeholder input from the beginning of the planning process can improve the odds of a successful implementation.
59 National T ransportation Safety Board, Reducing Speeding-Related Crashes Involving Passenger Vehicles, Safety
Study NT SB/SS-17/01, July 25, 2017, p. 42, at https://www.ntsb.gov/safety/safety-studies/Documents/SS1701.pdf.
60 A. S. Aeron-T homas and S. Hess, “Red-light Cameras for the Prevention of Road T raffic Crashes,” Cochrane
Database of System atic Reviews 2005, Issue 2, Art. No. CD003862; Charles Goldenbeld, Stijn Daniels, and Govert
Schermers, “ Red Light Cameras Revisited: Recent Evidence on Red Light Camera Safety Effects,” Accident Analysis
& Prevention, vol. 128, July 2019, pp. 139-147, at https://www.sciencedirect.com/science/article/pii/
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evidence that red light cameras, while reducing right-angle crashes at intersections, can lead to an
increase in rear-end collisions as drivers change their behavior to avoid entering intersections
when the traffic signal is yel ow and are run into from behind by more aggressive drivers. Such
collisions are typical y less destructive than the right-angle collisions resulting from red light
running, thus red light cameras reduce overal crash severity. 61 Not al studies have found
increases in rear-end collisions; nor have al studies found statistical y significant reductions in
overal crash severity.62
Use of Red Light Camera Enforcement
Red light cameras are used extensively in other countries.63 The first red light camera program in
the United States was introduced in New York City in 1992. By 2012 there were approximately
556 communities with red light camera programs across 25 states and the District of Columbia. 64
A backlash to the spread of red light cameras began around this time.65 According to the
Insurance Institute for Highway Safety, the number of communities with red light camera
programs has declined to approximately 340.66
The trend of declining support among drivers for automated speed enforcement seen in the AAA
Foundation for Traffic Safety’s series of surveys of traffic safety culture is also seen with regard
to red light cameras. In 2008, 70% of respondents somewhat or strongly supported red light
cameras, and 18% somewhat or strongly opposed them; in 2019, 43% somewhat or strongly
supported red light cameras, and 57% somewhat or strongly opposed them.67 This decline in
support may have been due partly to wel -publicized charges that some systems were ineffective
or abusive.68

S0001457518303610.
61 One study that looked at red light camera programs in seven cities (132 intersections) found that right -angle crashes
decreased by 25%, while rear-end collisions increased by 15%. Since the rear-end collisions were less severe than
right-angle crashes, the net benefit was estimated to be $39,000 (in 2001 dollars) per intersection per year. Forrest M.
Council, Bhagwant Persaud, and Kimberly Eccles, et al., Safety Evaluation of Red-Light Cam eras, IT S Joint Program
Office and Office of Safety Research and Development, Federal Highway Administration, FHWA-HRT -05-048,
Washington, DC, April 2005, at https://www.fhwa.dot.gov/publications/research/safety/05048/05048.pdf.
62 A fact sheet published by the Centers for Disease Control and Prevention (Centers for Disease Control and
Prevention, Automated Red Light Enforcem ent, “ Effectiveness,” (no date, “ page last reviewed December 2, 2015”), at
https://www.cdc.gov/motorvehiclesafety/calculator/factsheet/redlight.html) cites several reviews of the literature and
several individual studies supporting the effectiveness of red light camera programs in reducing overall crash severity,
but also cites several studies that found no reduction in overall crash severity. T he fact sheet notes that it is difficult t o
compare the studies directly, as they used a variety of methodologies, data sources, time periods, comparisons to
controls, and metrics to reach their conclusions, but concludes it seems “premature to conclude that red light cameras
have been widely found to be highly effective.”
63 Ibid.
64 Data from the Insurance Institute of Highway Safety, cited in National Highway T raffic Safety Administration,
Speed Enforcem ent Cam era System s Operational Guidelines, DOT HS 810 916, March 2008, p. 5, at
https://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa09028/resources/Speed%20Camera%20Guidelines.pdf.
65 Daniel C. Vock, “Why Cities Hit the Brakes on Red Light Cameras,” Governing, March 2015, at
https://www.governing.com/topics/public-justice-safety/gov-cities-hit -brakes-red-light-cameras.html.
66 Insurance Institute for Highway Safety, personal communication , August 26, 2020.
67 AAA Foundation for T raffic Safety, 2008 Traffic Safety Culture Index, T able 20, April 2008, at
https://aaafoundation.org/wp-content/uploads/2018/02/2008TSCIndexReport.pdf; 2019 Traffic Safety Culture Index,
T able 5, June 2020, at https://aaafoundation.org/wp-content/uploads/2020/06/2019-Traffic-Safety-Culture-Index.pdf.
68 Daniel C. Vock, “ Why Cities Hit the Brakes on Red Light Cameras,” Governing, March 2015, at
https://www.governing.com/topics/public-justice-safety/gov-cities-hit -brakes-red-light-cameras.html. See also David
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Automated Traffic Enforcement Issues
Some studies of red light camera programs have found that the number of crashes at intersections
increased, at least temporarily, after instal ation of red light cameras.69 Cameras may contribute to
an increase in rear-end crashes as a following vehicle runs into a vehicle that has stopped at a red
light. These crashes usual y cause only property damage while virtual y al studies have found
that the cameras reduce the number of right-angle crashes, which are more deadly.70 Nevertheless,
some critics object to red light cameras on the basis of the studies showing increases in rear-end
collisions.
Studies of speed management more broadly have found that infrastructure changes can be
effective in reducing speeding and red light running. For example, red light running can be
reduced by having a longer yel ow interval.71 A study of this approach in Philadelphia, PA, found
that increasing the yel ow interval by 1 second reduced red light violations by 36%. The study
also found that subsequently instal ing red light cameras at the same intersections decreased red
light violations a further 96%.72 Thus, increasing the yel ow-signal interval can result in
reductions in red light running violations, at least in the short term. Some studies have found that
over time drivers appear to adjust to increased yel ow intervals, with the result that some drivers
resume running the red lights.73 Also, increases in the yel ow interval are not without cost, as they
reduce the throughput capacity of the intersection.74
Some analysts assert that ATE systems do not work as wel as in-person enforcement to remove
risky drivers from the road: a speeding driver who is pulled over by an officer and is found to be
under the influence of alcohol can be removed from the road immediately and possibly suspended
from driving,75 whereas a speed camera would send a ticket to the driver’s (or vehicle owner’s)
address days later without inhibiting the driver’s activity for the rest of that trip. The documented
effect of speed camera programs in reducing injury crashes and fatalities suggests that the
deterrent effect of the increased possibility of a penalty provided by a speed camera program may
compensate for the delayed imposition of the penalty compared to the immediate but less certain

Kidwell, “How Chicago’s Red Light T icketing T urns Yellow Lights Into Cash,” Chicago Tribune, October 12, 2014, at
https://www.chicagotribune.com/news/ct-red-light-camera-yellow-light-1012-20141012-story.html, and David
Kidwell, “Redflex to Pay $20 Million to Chicago to Settle Lawsuit Over Red-Light Camera Bribery,” Chicago
Tribune, February 6, 2017, at https://www.chicagotribune.com/investigations/ct-red-light-cameras-lawsuit -settled-met-
20170206-story.html.
69 For example, a Federal Highway Administration study of red light camera programs in seven jurisdictions found an
overall increase in rear-end collisions and a reduction in right -angle crashes. Forrest M. Council, Bhagwant Persaud,
Kimberly Eccles, et al., Safety Evaluation of Red-Light Cam eras, FHWA-HRT -05-048, April 2005, at
https://www.fhwa.dot.gov/publications/research/safety/05048/05048.pdf.
70 Ibid. An economic analysis estimated that the value of the reduction in right -angle crashes was larger than the
increased cost of the rear-end collisions.
71 National Motorists Association, Yellow Light Timing, at https://www.motorists.org/issues/red-light-cameras/yellow-
lights/#:~:text=T his%20study%20shows%20that%20an,by%20at%20least%2050%20percent.
72 Richard A. Retting, Susan A. Ferguson, and Charles M. Farmer, Reducing Red Light Running T hrough Longer
Yellow Signal T iming and Red Light Camera Enforcement: Results of a Field Investigation, Insurance Institute for
Highway Safety, January 2007, at https://www.cob.org/wp-content/uploads/iihs-report_.pdf.
73 Ibid., p. 8.
74 Federal Highway Administration, Office of Safety, “ 5.7.3 Vehicle T iming –Vehicle Clearance,” Signalized
Intersections: An Inform ational Guide, at https://safety.fhwa.dot.gov/intersection/conventional/signalized/
fhwasa13027/ch5.cfm#s573.
75 Since many drivers continue to drive even though their licenses are suspended, the safety impact of license
suspension should not be exaggerated.
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penalty provided by in-person enforcement. Nevertheless, NHTSA recommends ATE as a
supplement to, not a replacement for, in-person speed enforcement.76
Some have questioned the constitutionality of ATE. The issues raised in this regard include
concerns that an automated enforcement ticket assumes that the offender is guilty until proven
innocent, rather than vice versa, and the lack of opportunity for offenders to confront their
accuser.77 Some courts have ruled against speed and red light camera programs on various
grounds; other courts have consistently rejected chal enges based on assertions that the programs
violate constitutional protections.78
In a 2010 House hearing on ATE,79 in which NHTSA and other witnesses testified to the
effectiveness of ATE in promoting safety, several Members and two witnesses asserted that
communities embraced ATE primarily to generate revenue rather than to improve safety, citing
instances of apparent bad faith in the operation of ATE programs.80 One study of Chicago’s red
light camera program, which found that the program resulted in reductions in right-angle crashes
and increases in rear-end crashes, reported that even community groups that acknowledged the
safety benefits of the program indicated that its value might be diminished by the perception that
it was intended to generate revenue.81 To al ay such concerns, NHTSA recommends transparency
on the part of ATE program administrators, along with a focus on the principle that the goal of the
program is to reduce the number of violations, not generate revenue.82
Issues for Congress
Restrictions on Use of Federal Funds
The federal government does not regulate the use of automated traffic enforcement. The decision
to al ow or prohibit the use of ATE is left to the states. But federal law can influence the decisions
of states and localities. Congress requires every state to have a highway safety program designed
to reduce traffic accidents and the resulting deaths, injuries, and property damage.83 Such
programs are required to address the following issues: speeding, driving while impaired,
aggressive and distracted driving, proper use of occupant protection devices (e.g., seat belts),

76 National Highway T raffic Safety Administration, Speed Enforcement Camera Systems Operational Guidelines, DOT
HS 810 916, March 2008, at https://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa09028/resources/
Speed%20Camera%20Guidelines.pdf.
77 Joel O. Christensen, “Wrong on Red: T he Constitutional Case Against Red-Light Cameras,” Washington University
Journal of Law & Policy, vol. 32, 2010, pp. 443-466, at https://openscholarship.wustl.edu/cgi/viewcontent.cgi?article=
1086&context=law_journal_law_policy.
78 Matthew S. Maisel, “Slave to the T raffic Light: A Road Map to Red Light Camera Legal Issues,” Rutgers Journal of
Law & Public Policy, vol. 10, no. 4, Spring 2013, pp. 401 -434.
79 U.S. Congress, House Committee on T ransportation and Infrastructure, Subcommittee on Highways and T ransit,
Utilization and Im pacts of Autom ated Traffic Enforcem ent, 111th Cong., 2nd sess., June 30, 2010.
80 See, for example, the written testimony of Dan Danila, representing the National Motorist Association, a group
totally opposed to AT E, at ibid.
81 Hani S. Mahmassani, Joseph L. Schofer, Breton L. Johnson, et al., Chicago Red Light Camera Enforcement: Best
Practices & Program Road Map, Northwestern University Transportation Center, March 17, 2017, at
https://www.transportation.northwestern.edu/docs/research/featured-reports/RLC-Report -Web.pdf.
82 National Highway T raffic Safety Administration, Speed Enforcement Camera Systems Operational Guidelines, DOT
HS 810 916, March 2008, at https://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa09028/resources/
Speed%20Camera%20Guidelines.pdf.
83 23 U.S.C. §402.
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accidents involving motorcycles, school buses, and commercial vehicles, and improvements to
law enforcement services in these regards. Congress has also established grant programs to
encourage states to take specific steps to address almost al of these issues. But Congress has not
created a program to encourage states to take specific steps to discourage speeding. The NTSB,
the GHSA, and other traffic safety organizations have urged Congress to add a speed
management grant program, since speeding is one of the leading contributors to traffic deaths.
In the 2012 surface transportation authorization act, Congress virtual y eliminated federal
financial support of ATE by limiting states’ discretion to spend federal funds for that purpose
except in school zones.84 This limitation was reiterated in the 2016 surface transportation
authorization act.
In a 2019 House hearing on highway safety, the NTSB testified that speed management is one of
its most wanted transportation safety improvements. It recommended expanded use of automated
speed enforcement.85
H.R. 2, a surface transportation reauthorization bil passed by the House of Representatives on
July 1, 2020, would make limited changes to the current federal policy toward ATE systems. It
would al ow states to spend their NHTSA Highway Traffic Safety formula funds to purchase,
operate, or maintain an ATE system in a school or work zone, and would require that any ATE
system that received federal funding comply with guidelines established by DOT.86
If Congress wishes to address the issue of speed management as part of its effort to reduce traffic
deaths and injuries, one option would be to remove the restrictions on ATE it imposed in 2012,
returning to its previous stance of al owing states and local government the discretion to use some
of their federal transportation funding to adopt automated enforcement programs without limiting
the location of the cameras. Alternatively, Congress could continue its current policy.
Speed Management Incentive Grants
The GHSA and the NTSB have cal ed upon Congress to create a grant program to encourage
states to address speeding. Should Congress decide to create such a program, it might include
automated enforcement, NHTSA’s highest-rated measure to address speeding, as part of the
program. Such a program could address the issues identified here by (a) removing, or waiving for
the purposes of this program, the restrictions on federal funding for the implementation of ATE;
(b) making eligibility for a grant contingent on use of speed cameras and compliance with a
majority of NHTSA’s operational guidelines for speed camera programs; (c) making eligibility
for a grant dependent on a state treating speed and red light camera violations like moving traffic
violations, as NHTSA’s guidelines recommend; and (d) making eligibility for a grant contingent
on al owing communities to locate speed cameras in locations in addition to school and work
zones.
State Restrictions on Use of ATE
In most states that permit ATE, state legislation limits the locations where ATE can be used. The
most common restriction is limiting automated speed enforcement to school zones. The NTSB

84 See footnote 54 for details.
85 U.S. Congress, House Committee on T ransportation and Infrastructure, Subcommittee on Highways and T ransit,
Every Life Counts: Im proving the Safety of Our Nation ’s Roadways, 116th Cong., 1st sess., April 9, 2019.
86 H.R. 2 (116th Congress), §3002(2).
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noted that school zones are not locations at high risk for speeding-related injuries and death; just
seven of the estimated 9,283 U.S. speeding-related fatalities in 2014 occurred in school zones.87
This point was echoed by representatives from agencies with automated speed enforcement
programs.88 If it wishes to encourage more effective use of automated enforcement, Congress
could make states’ eligibility for certain transportation grants contingent on al owing
communities to locate speed cameras in locations in addition to school and work zones. Such an
approach might lead to some states that are currently eligible for such grants to become not
eligible until and unless they change their legal treatment of ATE.89
Legal Status of ATE Violations
The treatment of individuals caught speeding and running red lights by automated devices
appears to make a difference in the deterrent effects of the programs. One study found that several
cities in states that treat the citations like parking violations (no points on a license, minimum fine
of $35 to $75) had higher repeat offender rates than did several cities in states where the citations
were treated like moving traffic violations (minimum fines of $160 to $280, points assessed
against a driver’s license).90 The study also found that the speed camera ticket payment rate was
lower in the cities in the former category.91
In states that do not have a law addressing ATE, some communities have implemented camera
enforcement programs under general traffic laws.92 An NTSB study found that officials of
transportation departments in states that lacked automated speed enforcement legislation expected
that implementing an automated enforcement program in the absence of an enabling law would
subject the program to significant legal chal enges.93
Traffic violations are matters of state, not federal, law. However, Congress could encourage states
to increase the deterrent effect of speeding and red light violations detected by ATE. One
approach would be to make eligibility for certain transportation grants dependent on a state
treating speed and red light camera violations like moving traffic violations, as NHTSA
recommends. Such an approach might lead to some states that are currently eligible for such
grants to become not eligible until and unless they change their legal treatment of ATE.

87 National T ransportation Safety Board, Reducing Speeding-Related Crashes Involving Passenger Vehicles, Safety
Study NT SB/SS-17/01, July 25, 2017, p. 40, at https://www.ntsb.gov/safety/safety-studies/Documents/SS1701.pdf.
88 Ibid., pp. 40-41.
89 Such an approach could involve creating a new grant program, with such a requirement for eligibility, along the lines
of the incentive grant programs in 23 U.S.C. §405, or adding such a requirement to existing grant programs, along the
lines of 23 U.S.C. §164; if the latter, the penalty could involve transferring a portion of the state’s grant to its highway
safety program, as in 23 U.S.C. §164, or withholding a po rtion of the funding, as in 23 U.S.C. §161.
90 Scott Calvert, Paul Overberg, and Max Rust, “Speed Cameras: T he Cities with the Worst Offenders,” Wall Street
Journal, December 22, 2019.
91 Ibid. T he reason for the higher rate of payment for the citations in the cities where the fines were higher was not
clear.
92 For example, nine cities in Iowa (including the four largest cities: Des Moines, Davenport, Cedar Rapids, and Sioux
City) and Hannibal, MO. See Missouri and Iowa biennial AT E survey reports submitted to NHT SA at
https://www.nhtsa.gov/highway-safety-grants-program/2018-automated-traffic-enforcement-system.
93 National T ransportation Safety Board, Reducing Speeding-Related Crashes Involving Passenger Vehicles, Safety
Study NT SB/SS-17/01, July 25, 2017, p. 40, at https://www.ntsb.gov/safety/safety-studies/Documents/SS1701.pdf.
Congressional Research Service
17

Safety Impact of Speed and Red Light Cameras

Direct DOT to Update its Operational Guidelines
NHTSA’s speed camera program operational guidelines94 have not been updated since their
publication in 2008. As the NTSB has pointed out, the guidelines do not include information
about recent innovations such as point-to-point cameras. 95 Also, the NTSB found that the
guidelines were not wel known among agencies operating speed camera programs. Congress
could direct NHTSA to issue updated guidelines in order to bring more attention to the
information and improve the conduct of speed camera programs.

Author Information

David Randall Peterman

Analyst in Transportation Policy

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94 National Highway T raffic Safety Administration, Speed Enforcement Camera Systems Operational Guidelines, DOT
HS 810 916, March 2008, at https://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa09028/resources/
Speed%20Camera%20Guidelines.pdf.
95 National T ransportation Safety Board, Reducing Speeding-Related Crashes Involving Passenger Vehicles, Safety
Study NT SB/SS-17/01, July 25, 2017, p. 42, at https://www.ntsb.gov/safety/safety-studies/Documents/SS1701.pdf.
Congressional Research Service
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