Red light running
Maintaining public support
Red light running happens frequently and is often deadly. In 2017, 890 people were killed in crashes that involved red light running.
Red light cameras are an effective way to discourage red light running. Enforcement is the best way to get people to comply with any law, but it's impossible for police to be at every intersection. Cameras can fill the void. An IIHS study found that cameras reduced the fatal red light running crash rate of large cities by 21 percent and the rate of all types of fatal crashes at signalized intersections by 14 percent.
Cameras don't violate privacy. Driving is a regulated activity, and people who obtain licenses are agreeing to abide by certain rules. Red light cameras are a way to catch people who break those rules, just like traditional enforcement.
Proper signal timing makes intersections safer. Adequate yellow time reduces red light running and leads to fewer crashes.
By the numbers
Red light runners cause hundreds of deaths and tens of thousands of injuries each year.
In 2017, 890 people were killed in crashes that involved red light running. Over half of those killed were pedestrians, bicyclists and people in other vehicles who were hit by the red light runners.
In 2017, an estimated 132,000 people were injured in red light running crashes.
Red light running defined
If a vehicle enters an intersection any time after the signal light has turned red, the driver has committed a violation. Motorists who are inadvertently in an intersection when the signal changes (waiting to turn left, for example) are not red light runners.
In locations where a right turn on red is permitted, drivers who fail to come to a complete stop before turning may be considered red light runners. Violations also include people turning right on red at intersections where doing so is prohibited.
A study conducted during several months at five busy intersections in Fairfax, Va., prior to the use of red light cameras, found that, on average, a motorist ran a red light every 20 minutes at each intersection ( Retting et al., 1999 ). During peak travel times, red light running was more frequent.
An analysis of red light violation data from 19 intersections without red light cameras in four states found a violation rate of 3.2 per hour per intersection ( Hill & Lindly, 2003 ).
Who runs red lights?
In a 2017 national telephone survey by the AAA Foundation for Traffic Safety, 93 percent of drivers said it's unacceptable to go through a red light if it's possible to stop safely, but 43 percent reported doing so in the past 30 days ( AAA Foundation for Traffic Safety, 2018 ).
Among drivers involved in 2017 fatal red light running multiple-vehicle crashes, the red light runners were more likely than other drivers to be male, to be younger, and to have prior crashes or alcohol-impaired driving convictions. The red light runners also were more likely to be speeding or alcohol-impaired at the time of the crash and less likely to have a valid driver's license.
Providing adequate yellow signal time is important and can reduce crashes. Studies have shown that increasing yellow timing to values associated with guidelines published by the Institute of Transportation Engineers can significantly decrease the frequency of red light violations and reduce the risk of total crashes, injury crashes and right-angle crashes ( Bonneson & Zimmerman, 2004 ; Retting & Greene, 1997 ; Van Der Horst, 1988 ; McGee et al., 2012 ).
Adjusting yellow signal time alone may not be enough. An IIHS study conducted in Philadelphia evaluated effects on red light running of first lengthening yellow signal timing by about a second and then introducing red light cameras ( Retting et al., 2008 ). While the longer yellow reduced red light violations by 36 percent, adding camera enforcement further cut red light running by another 96 percent.
How red light cameras work
Red light cameras automatically photograph vehicles that go through red lights. The cameras are connected to the traffic signal and to sensors that monitor traffic flow just before the crosswalk or stop line. The system continuously monitors the traffic signal, and the camera captures any vehicle that doesn't stop during the red phase. Many red light camera programs provide motorists with grace periods of up to half a second after the light switches to red.
Where red light cameras are used, it's standard practice for trained police officers or authorized civilian employees to review every picture or video clip to verify vehicle information and ensure the vehicle is in violation. A ticket is issued only if there is clear evidence the vehicle ran a red light ( Eccles et al., 2012 ).
In most states, red light camera citations are treated as civil offenses rather than moving violations. This means that there are no driver license points assessed and no insurance implications. In some states, the law specifically prohibits insurers from considering red light camera citations in determining premiums or renewals. In a few states (Arizona, California, Oregon) red light camera citations are treated the same as citations issued by police officers doing traffic enforcement.
State laws on automated enforcement
In some jurisdictions, state law makes the vehicle owner responsible for the ticket by establishing a presumption that the registered owner is the vehicle driver at the time of offense. This type of legislation provides a mechanism for vehicle owners to inform authorities if someone else was driving.
Another option is to treat violations captured by red light cameras as the equivalent of parking tickets. If, as in New York, red light camera violations are treated like parking citations, the law can make registered vehicle owners responsible without regard to who was driving at the time of the offense.
In either case, the locality must provide a process for appealing the ticket. Grounds for appeal may include, for example, evidence that the vehicle has been stolen, that a warning sign was missing from the intersection when the authorizing law requires a sign, or that the vehicle moved into the intersection to make way for an emergency vehicle.
Automated enforcement doesn't violate privacy because driving is a regulated activity on public roads. By obtaining a license, a motorist agrees to abide by certain rules, such as to obey traffic signals. There's no legal or common-sense reason drivers shouldn't be observed on the road or have their violations documented.
Effectiveness of cameras
Red light cameras have been shown to reduce both red light violations and crashes.
A series of IIHS studies in different communities found that red light violations are reduced significantly with cameras. Institute studies in Oxnard, California, and Fairfax, Virginia, reported reductions in red light violation rates of about 40 percent after the introduction of red light cameras ( Retting et al., 1999 ; Retting et al., 1999 ). In addition to the decrease in red light running at camera-equipped sites, the effect carried over to nearby signalized intersections not equipped with red light cameras.
A more recent IIHS study in Arlington, Va., also found significant reductions in red light violations at camera intersections one year after ticketing began ( McCartt & Hu, 2014 ). These reductions were greater the more time had passed since the light turned red, when violations are more likely to result in crashes.
Violations occurring at least a half second after the light turned red were 39 percent less likely than would have been expected without cameras. Violations occurring at least 1 second after were 48 percent less likely, and the odds of a violation occurring at least 1.5 seconds into the red phase fell 86 percent.
When it comes to crash reductions, an IIHS study comparing large cities with red light cameras to those without found the devices reduced the fatal red light running crash rate by 21 percent and the rate of all types of fatal crashes at signalized intersections by 14 percent ( Hu & Cicchino, 2017 ).
Previous research in Oxnard, California, found significant citywide crash reductions followed the introduction of red light cameras, and injury crashes at intersections with traffic signals were reduced by 29 percent ( Retting & Kyrychenko, 2002 ). Front-into-side collisions — the crash type most closely associated with red light running — at these intersections declined by 32 percent overall, and front-into-side crashes involving injuries fell 68 percent.
The Cochrane Collaboration, an international public health organization, reviewed 10 controlled before-after studies of red light camera effectiveness ( Aeron-Thomas & Hess, 2005 ). Based on the most rigorous studies, there was an estimated 13-29 percent reduction in all types of injury crashes and a 24 percent reduction in right-angle injury crashes.
Some studies have reported that while red light cameras reduce front-into-side collisions and overall injury crashes, they can increase rear-end crashes. However, such crashes tend to be much less severe than front-into-side crashes, so the net effect is positive.
A study sponsored by the Federal Highway Administration evaluated red light camera programs in seven cities ( Council et al., 2005 ). It found that, overall, right-angle crashes decreased by 25 percent while rear-end collisions increased by 15 percent. Results showed a positive aggregate economic benefit of more than $18.5 million in the seven communities.
The authors concluded that the economic costs from the increase in rear-end crashes were more than offset by the economic benefits from the decrease in right-angle crashes targeted by red light cameras.
Not all studies have reported increases in rear-end crashes. The review by the Cochrane Collaboration did not find a statistically significant change in rear-end injury crashes ( Aeron-Thomas & Hess, 2005 ).
When camera programs are discontinued, crash rates go up.
An IIHS study compared large cities that turned off red light cameras with those with continuous camera programs. In 14 cities that shut down their programs during 2010-14, the fatal red light running crash rate was 30 percent higher than would have been expected if they had left the cameras on. The rate of fatal crashes at signalized intersections was 16 percent higher ( Hu & Cicchino, 2017 ).
A study in Houston, which turned off red light cameras in 2011, found that the camera deactivation was associated with a 23 percent increase in right-angle red light running crashes at the intersections that previously had cameras ( Ko et al., 2017 ).
Communities using red light cameras
The number of communities using red light cameras has increased dramatically since the first camera program was implemented in 1992 in New York City. During 2018, 403 U.S. communities operated red light camera programs, according to media sources and other public information tracked by IIHS.
Although new camera programs continue to be added, the total number of camera programs has declined since 2012 because more programs have been discontinued than have been initiated.
Commonly cited reasons for turning off cameras include a reduction in camera citations, difficulty sustaining the financial viability of the program (for example, because fines from the camera citations are shared with state government or because violators don't pay their fines) and community opposition.
Trends in the number of U.S. communities with red light camera programs
Major U.S. cities with red light cameras include Atlanta, Chicago, Dallas, Denver, New Orleans, New York City, Philadelphia, Phoenix, San Francisco, Seattle and Washington, D.C.
State laws on automated enforcement
Maintaining public support
Like other government policies and programs, camera enforcement requires acceptance and support among the public as well as elected officials. Some opponents of automated enforcement raise the "big brother" issue, and voters in some cities have rejected cameras.
Still, acceptance of cameras always has been strong. A 2011 IIHS survey in 14 big cities with longstanding red light camera programs found that two-thirds of drivers support their use ( McCartt & Eichelberger, 2012 ). A 2012 IIHS survey conducted in Washington, D.C., which has an extensive camera program, found that 87 percent of residents support red light cameras ( Cicchino et al., 2014 ).
Programs have the best chance of earning community support if they are designed to improve safety by modifying driver behavior and not to generate revenue.
In 2018, IIHS teamed up with AAA, Advocates for Highway and Auto Safety and the National Safety Council to create a red light camera checklist for communities . The checklist provides practical instructions for planning, implementing and evaluating red light camera programs, including steps to help communities build and maintain public support.
First steps include careful assessment of intersections where red light running is a problem. Communities need to ensure that steps are taken to evaluate road design and signal timing.
The checklist recommends that policymakers organize a community advisory committee made up of stakeholders such as law enforcement, victim advocates, school officials and residents to make suggestions on the development of a program.
To the extent feasible, revenue generated by the program should be allocated toward traffic safety programs.
In the long term, communities should plan for regular program evaluation based on crash and infraction data. The guide discourages simple before-and-after comparisons of crashes because the numbers can be skewed by factors such as the ups and downs of the economy. Instead, comparisons should be made using proper control intersections that are not subject to the known "spillover effect," whereby crashes are reduced at intersections throughout a community, not just at the camera sites.
The recommendations are based on input from law enforcement and community leaders and on best practice guidelines published by the National Cooperative Highway Research Program, which is funded by state departments of transportation and administered by the Transportation Research Board.
Updated May 2019