Research

Documented evidence of photo enforcement's safety benefits has been recorded in the U.S and around the world, reinforced by new reports and studies showing that red light cameras lead to significant decreases in intersection violations and crashes and that speed cameras lead to decreases in crashes. As a supplement to traditional law enforcement, red light cameras and speed enforcement cameras can bring about behavior changes resulting in more motorists obeying traffic signals and speed limit signs and avoiding the crashes, injuries and loss of life caused by red light running and speeding.

Listed below are selected studies. Visit again soon for additional studies.

Speed Studies

Study recommends Speed Cameras in NYC.

Thirty-nine percent of New York City drivers were caught speeding in a study released in February, 2009 by Transportation Alternatives, a bicycling and pedestrian safety advocacy group. The report, Terminal Velocity: NYC’s Speeding Epidemic, shows out of control speeding in neighborhoods across the city’s five boroughs and calls for speed enforcement cameras as a common-sense way to restore order and safety to New York City’s streets. Read the full report.

Evaluation of Automated Speed Enforcement in Montgomery County, Maryland (Retting, Farmer, McCartt, 2008)

In 2007, Montgomery Co. implemented Maryland’s first automated speed enforcement program, with camera use limited to residential streets and school zones. Vehicle speeds were measured approximately 6 months before and 6 months after speed cameras were deployed and signs were installed warning of the speed enforcement program. Relative to comparison sites in Virginia, the proportion of drivers traveling more than 10 mph above posted speed limits declined by about 70 percent at Montgomery County locations with both warning signs and speed camera enforcement, 39 percent at locations with warning signs but no speed cameras, and 16 percent on residential streets with neither warning signs nor speed cameras. Read the full report.

Speed cameras on Arizona’s Loop 101 lead to lower speeds, safer drivers, shorter drive times and economic savings.

Read Simon Washington’s full report.

NHTSA’s Speed Enforcement Camera Systems Guidelines (March 2008)

Guidelines note that automated speed enforcement (ASE) systems are an important element in speed management and can be a very effective countermeasure to prevent speeding-related crashes. Read the full report.

Red Light Camera Studies

Texas study finds significant drop in crashes at red light camera intersections

In a study of 56 intersections in 12 Texas cities reporting pre and post-installation crash data, there was a 30% decrease in annualized crashes and a 43% reduction in right angle crashes. There was a slight increase, 5%, or approximately 5 additional crashes, attributed to rear end collisions. Read the full report.

Iowa study finds red light cameras lead to dramatic drop in crashes

This 2007 study found a 40 percent reduction in red light running crashes in Davenport and a 90 percent reduction in Council Bluffs. Read a summary of The Effectiveness of Iowa’s Automated Red Light Running Programs.

Yellow Light Timing Studies

Yellow light timing study finds longer warning period leads to more crashes. Read the study.

A look at the position of the National Campaign to Stop Red Light Running and observations from engineers and leading researchers. Read complete article

Other Recent Findings

National Highway Traffic Safety Administration

The University of North Carolina Highway Safety Research Center has published the 4th edition of Countermeasures That Work, a reference guide to assist State Highway Safety Offices in selecting effective, science-based traffic safety countermeasures for major highway safety problem areas. Funded by the National Highway Traffic Safety Administration, the guide contains a chapter for each problem area. It cites photo enforcement as an effective countermeasure for speeding and red light running. Click here for the full report. Of particular interest are pages 3-5, 3-11 and 3-12.

Philadelphia, PA

A 2007 study of the Philadelphia, PA red light camera program conducted by the Insurance Institute for Highway Safety tracked signal violation rates at intersections before and after extending the yellow light sequence and again after red light camera enforcement had been in effect for about a year. The first step reduced signal violations by 36 percent. The cameras reduced the remaining violations by 96 percent. At the same time, violations were virtually unchanged at two control group intersections. Read an article about the study and the Philadelphia program.

Virginia Beach, VA

A multi-year study of the red light camera program in Virginia Beach found that red light running violations more than tripled after the law that permitted the city to use red light cameras was allowed to expire in 2005. The results showed that red light cameras provided a strong deterrent against red light running and that once the cameras were turned off, aggressive drivers returned to their old habits. Read the study abstract.

U.S. Federal Highway Administration

A 2005 U.S. Federal Highway Administration-funded study estimated total societal cost reductions from red light camera programs in seven U.S. cities to be over $14 million per year, or over $38,000 for each studied red light camera location. Read the executive summary.

Cochrane Collaboration

A 2005 review of 10 U.S. and international research studies on red light cameras conducted by the respected Cochrane Collaboration, a U.K.-based research organization found that “Red-light cameras are effective in reducing total casualty crashes…. In the best conducted of these studies, the reduction was nearly 30%.” Read the full study.

Bibliography of Selected U.S and International Red Light Running/Camera Enforcement Studies

American Association of State Highway and Transportation Officials. 2006. Use of Automated Traffic Enforcement to Improve Safety. Washington, D.C.: ( Policy Resolution PR-14-06)

Andes, J. 2006. “Red-light cameras reducing crashes; Number of tickets issued also down as fewer test system”. The Columbus Dispatch. Columbus, OH:

Antonucci, N. et al. 2004. NCHRP: Report 500: Guidance for Implementation of the AASHTO Strategic Highway Safety Plan: Volume 12, A Guide for reducing collisions at signalized intersections. http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_500v12.pdf .

Blackburn R.R., and Gilbert, D.T. 1995. Photographic enforcement of traffic laws. Washington, D.C.: (National Cooperative Highway Research Program, Synthesis of Highway Practice 219, Transportation Research Board).

Blakey, L. 2003. “Red Light Cameras: Effective Enforcement Measures for Intersection Safety,” Institute of Transportation Engineers Journal . Washington, D.C.: (March 2003).

Bonneson, J. and Zimmerman, K. 2004. “Effect of Yellow Interval Timing On Red-Light Violation Frequency at Urban Intersections”. Transportation Research Record . Washington, D.C.: (Texas Transportation Institute, The Texas A & M University, 2004).

Bonneson, J. and Zimmerman, K. 2004. Development of Guidelines for Identifying and Treating Locations with a Red-light Running Problem . College Station, TX: (Texas Transportation Institute, The Texas A & M University, 2004).

Bonneson, J.A.; Zimmerman, K.H.; and Pratt, M.P. 2005. Red-light-running Handbook Workshop Series: Year 1 Summary Report. Austin TX: (Texas Department of Transportation, 2005).

Bonneson, J.A.; Zimmerman, K.H.; and Quiroga, C. 2003. Review and Evaluations of Enforcement Issues and Safety Statistics Related to Red-Light Running . College Station, TX: (Texas Transportation Institute, The Texas A&M University System, September 2003).

Bureau of State Audits. 2002. Red Light Camera Programs: Although They Have Contributed to a Reduction in Accidents, Operational Weaknesses Exist at the Local Level . California State Auditor. Sacramento, CA: (2001-125, July 2002).

Calgary Police Service. 2006. Red Light Camera Program. http://www.calgarypolice.ca/sections/traffic/redlight.html. C

City of Dallas, TX. 2006. “ Dallas Automated Red Light Enforcement Camera Program: Procurement Process Overview, Lessons Learned And Site Selection Process . Dallas, TX: (October 2006).

City of Garland, TX Transportation Department. 2006. Report on the Effectiveness of Automated Red Light Enforcement . Garland, TX: (September 2006).

City of Mesa, AZ. 2006. 2006 City of Mesa Red Light Camera Public Opinion Survey Results . Mesa, AZ: (April 2006).

City of Paradise Valley, AZ. 2006. Photo Enforcement Program . http://www.ci.paradise-valley.az.us/police/photoenforcement.html

City of San Francisco: Department of Parking and Traffic. 2006. Red Light Photo Enforcement Program. http://www.sfgov.org/site/livablestreets_index.asp?id=14440 .

City of Ventura, CA. “City of Ventura Administrative Report: Renewal of Contract with Redflex Systems”. (May 22 nd , 2006).

Click, S.M., and Jones, D.L. 2006. Calculation of Yellow Change and All-Red Clearance Intervals: The North Carolina Experience. McLean, VA: ( Transportation Research Board Annual Meeting 2006, Paper #06-1099, 2006).

Council, F. et al. 2005. Crash Cost Estimates by Maximum Police-Reported Injury Severity within Selected Crash Geometries . Washington, D.C.: (Federal Highway Administration HRT-05-051, U.S. Department of Transportation, 2005).

Federal Highway Administration. 2003. Guidance for Using Red Light Cameras . Washington, D.C.: (Federal Highway Administration, National Highway Traffic Safety Administration, Publication No. FHWA-SA-03-018, March 2003).

Federal Highway Administration. 2007. Intersections: Intersection Safety Facts and Statistics. http://safety.fhwa.dot.gov/intersections/inter_facts.htm .

Federal Highway Administration. 2004. Intersection Safety Issue Briefs , Washington, D.C.: (Federal Highway Administration and Institute of Transportation Engineers, 2004).

Flannery, A. and Maccubbin. R. 2002. Using Meta Analysis Techniques to Assess the Safety Effect of Red Light Running Cameras. Washington, D.C.: (Prepared for the Federal Highway Administration, EDL No. 13623, 2002).

Gains, A. 2003. A cost recovery system for speed and red-light cameras: Two year pilot evaluation. London, UK: (Department of Transport, 2003).

Garber, N.J. et al. 2005. An Evaluation of Red Light Camera (Photo-Red) Enforcement Programs in Virginia: A Report in Response to a Request by Virginia's Secretary of Transportation. Charlottesville, VA: ( Virginia Transportation Research Council, VTRC 05-R21, January 2005).

Gardner, Per. 2004. Traffic Signal Safety: Analysis of Red-Light Running in Maine . Orono, ME: (Department of Civil & Environmental Engineering, University of Maine, May 2004).

Golob, J.M. et al. 2003. Impacts of the San Diego Photo Red Light Enforcement System on Traffic Safety. Washington, D.C.: (Presented at Transportation Research Board meeting, 2003).

Henry, RD. 2005 Signal Timing on a Shoestring Washington, D.C.: (Federal Highway Administration, Publication No. FHWA-HOP-07-006, March 2005).

Hill, S. and Lindly, J. 2004.“Red Light Running Prediction And Analysis”. Transportation Research Record . Washington, D.C.: (Department of Civil and Environmental Engineering, The University of Alabama, 2004).

Huang, H.; Chin, H.C.; and Heng, A.H.H. 2006. Effect of Red Light Camera on Accident Risk at Intersections . Washington, D.C.: (presented at the 2006 National Transportation Board Annual Meeting, 2006).

Hunter, W.W. 2004. The Use of Red-light-running Automated Enforcement Equipment in North Carolina: A Descriptive Summary . North Carolina: (Prepared for AAA of the Carolinas, 2004).

Insurance Institute for Highway Safety. 2006. Automated Enforcement Laws. http://www.ncutlo.org/autoenforce622.htm.

Insurance Institute for Highway Safety. 2006. Communities with Red Light Cameras (as of July 2006) IIHS webpage . http://www.iihs.org/research/topics/rlc_cities.html

Insurance Institute for Highway Safety. 2005. Q&A Red Light Cameras (as of December, 2005) IIHS webpage. http://www.iihs.org/research/qanda/rlr.html#12 .

International Association of Chiefs of Police. 2004. Highway Safety Desk Book . Alexandria, VA: (September 2004).

Kraus, E. and Quiroga, C. 2003. Legislative Issues Related to Automated Enforcement of Red Light Running. Washington, DC: (Presented at Transportation Research Board meeting, Paper No. 03-3308, 2003).

Kraus, E., and Quiroga. C. 2004. “Red Light Running Trends In Texas,”. Transportation Research Record . Washington, D.C.: (Texas Transportation Institute, The Texas A & M University, 2004).

Kriz, K.; Moran, C.; and Regan, M. 2006. An Analysis of a Red-Light Camera Program in the City of Milwaukee. Milwaukee, WI: (Board of Regents of the University of Wisconsin System, 2006).

Lum, K.; Wong, P.; and Wong, Y. 2003. “A Before-and-After Study on Red-Light Camera Installation”, ITE Journal . Washington, D.C.: (March 2003).

Mahalel, D. and Prashker, J.N. 1987. "A Behavioral Approach to Risk Estimation of Rear-End Collisions at Signalized Intersections." Transportation Research Record. Washington, D.C.: (Record 1114, 96-102).

McGee, H.W. 2003. Making Intersections Safer: A Toolbox of Engineering Countermeasures to Reduce Red-Light Running . Washington, D.C.: ( The Institute of Transportation Engineers, 2003).

McGee, H.W. and Eccles, K.A. 2003. "Impact of Red Light Camera Enforcement on Crash Experience," NCHRP Synthesis 310 . Washington, D.C.: (National Cooperative Highway Research Program, Transportation Research Board, 2003).

Milazzo, II, J.; Hummer, J.; and Rouphail, N.M. 2003. Red Light Running: Dilemma Zones, Photo Enforcement Tolerances, Policy Recommendations. Raleigh, NC: (presented at the 2003 Lifesavers Conference on National Highway Safety Priorities, 2003).

Milazzo, II, J. 2005. Operational and Policy Perspectives on Red-Light Camera Programs.

Raleigh, NC: (Transportation Research Board, 2005).

Miller, J. et. al.2006. Safety Impacts of Photo-Red Enforcement at Signalized Intersections: An Empirical Bayes Approach . Charlottesville, VA: (Virginia Transportation Research Council and the University of Virginia, presented at Transportation Research Board meeting, 2006).

Nambisan, S. 2007. A Comparative Evaluation of the Safety Performance of Roundabouts and Traditional Intersection Controls , Institute of Transportation Engineers Journal . Washington, D.C.: (March 2007).

National Committee on Uniform Traffic Laws and Ordinances. 2004. Automated Traffic Law Enforcement Model Law . www.ncutlo.org/autoenforce622.htm .

Passetti, K. 1997. Use of Automated Enforcement for Red Light Violations . College Station, TX: (Department of Civil Engineering, The Texas A&M University, 1997).

PB Farradyne Inc. 2002. City of San Diego Photo Enforcement System Review Final Report. Commissioned by the City of San Diego Police Department.

Peek Traffic Systems. 2006. Automated Red Light Enforcement – A Pilot Study . Palmetto, FL: (2006).

Peden M. et al, eds. The World Report on Road Traffic Injury Prevention. World Health Organization, Geneva: (2004).

Peota, C. 2006. “Public Health Enemy #1”. Minnesota Medicine. Minneapolis, MN: (Minnesota Medical Association, Volume 89, May 2006).

Quiroga, C. et al. 2003 . Red Light Running – A Policy Review . College Station, TX: (Center for Transportation Safety, Texas Transportation Institute, The Texas A&M University, 2003).

Radwan, E. et al. 2005. Red-light Running and Limited Visibility Due to LTV's Using the UCF Driving Simulator. Orlando, FL: (Center for Advanced Transportation Systems Simulation, University of Central Florida, Florida Department of Transportation, 2005).

Redelmeier, D. 2003. "Traffic-Law Enforcement and Risk of Death from Motor-Vehicle Crashes: Case-Crossover Study". The Lancet. New York, NY: ( Volume 361, June 28 th , 2003): 2177-2182.

Retting, R.A. 2004. Photo Enforcement Issues. Washington, D.C.: (Virginia Transportation Conference, Insurance Institute for Highway Safety, October 2004).

Retting, R.A. 2003. “Speed cameras — public perceptions in the US”. Traffic Engineering and Control. London, UK: (Volume 44, March 2003): 100-101.

Retting, R.A.; Ferguson, S.A.; and Hakkert, A.S. 2003. “Effects of red light cameras on violations and crashes: a review of the international literature”. Traffic Injury Prevention. Philadelphia, PA: (Volume 4, 2003):17-23.

Retting, R.A.; Kyrychenko, S. 2001. Crash Reductions Associated with Red Light Camera Enforcement in Oxnard, California . Arlington, VA: (Insurance Institute for Highway Safety, April 2001).

Retting, R.A. et al. 1999. “Evaluation of red light camera enforcement in Fairfax, Va., USA”. Institute of Transportation Engineers Journal . Washington, DC: (August 1999).

Rodegerdts, L. et al. 2007. NCHRP: Report 572: Roundabouts in the United States: Washington, D.C.: (National Cooperative Highway Research Program, (Transportation Research Board) http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_572.pdf

Sisiopiku, V. 2002. Assessment of Red Light Running Camera Enforcement Technologies . 2002. East Lansing, MI: (Department of Civil and Environmental Engineering, Michigan State University, Presented at the Transportation Research Board, January 2002).

Washington, S. and Shin, K. 2005. The Impact of Red Light Cameras (Automated Enforcement) on Safety in Arizona . Phoenix, Arizona.: (Arizona Department of Transportation, 2005).

Yang, C.; Wassim, N.2006. Analysis of red light violations data collected from intersections equipped with red light photo enforcement cameras. National Highway Traffic Safety Administration. Washington, D.C.: (DOT HS 810 580)

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