Estimating the Safety Benefits of Red Light Cameras at Signalized Intersections in Urban Areas Case Study: The City of Virginia Beach

Document Type: Research Paper


1 Department of Civil and Environmental Engineering, Postdoctoral Assistant, Virginia Modeling, Analysis and Simulation Center , Old Dominion University, Virginia, USA

2 Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, USA

3 Center for Innovative Transportation Solutions Virginia Modelling, Analysis and Simulation Center Old Dominion University, Virginai, USA


The Highway Safety Manual [HSM, 2010] recommends safety evaluations be performed before implementing any roadway treatment to predict the expected safety consequences. Safety consequences can be measured using crash prediction models, Crash Modification Factor (CMFs), or both. This paper develops a CMF to show the expected impact of red-light cameras (RLCs) on safety at signalized intersections. A CMF is a multiplicative factor used to compute the expected number of crashes after implementing a given countermeasure at a specific roadway site. RLCs are intended to improve driver’s alertness to avoid causing accidents. This paper analyzes accident data reported at thirteen signalized intersections in Virginia Beach in 2008 before the RLCs were installed and 2010 after the RLCs were installed. Safety performance functions (SPFs) and the empirical Bayes (EB) before-after methodologies are used to develop a CMF for this countermeasure. The result shows an overall CMF of 0.846, which is a 15.4% safety improvement. This result is not absolute; however, but sets a starting point for further investigations and potential inclusion in the future editions of the HSM.


- Elvik, R. (2008) “The predictive validity of empirical Bayes estimates of road safety”, Accident Analysis & Prevention, 40(6), pp.1964- 1969.

- Erke, A. (2009) “Red light for red-light cameras? A meta-analysis of the effects of red-light cameras on crashes”. Accident Analysis & Prevention, 41(5), 897-905.

- Garber, N. J., Miller, J. S., Eslambolchi, S., Khandelwal, R., Mattingly, K. M., Sprinkle, K. M. and Wachendorf, P. L. (2005) “Evaluation of red light camera (photo-red) enforcement programs in Virginia: a report in response to a request by Virginia’s secretary of transportation (No. VTRC 05-R21,)”.


- Gross, F., Persaud, B. and Lyon, C. (2010) “A guide to developing quality crash modification factors” (No. FHWA-SA-10-032).

- Hauer, E. (1997) “Observational before—after studies in road safety: estimating the effect of highway and traffic engineering measures on road safety”, Elsevier Science Ltd, 6, 7.

- Hauer, E., Harwood, D., Council, F. and Griffith, M. (2002) “Estimating safety by the empirical Bayes method: a tutorial”, Transportation Research Record: Journal of the Transportation Research Board, (1784), pp.126-131.

- Hieatt, K. (2011) “Study: Virginia Beach redlight cameras offer mixed results” , The Virginian-Pilot. redlight-cameras-offer-mixed-results#

- Hu, W., McCartt, A. T. and Teoh, E. R. (2011) “Effects of red light camera enforcement on fatal crashes in large us cities”. Journal of safety research, 42(4), pp.277-282.

- Insurance Institute for Highway Safety, IIHS. (2007) “Status Report”, Vol. 42, No. 1. 01.pdf

- Lum, K. M. and Wong, Y. D. (2003) “A beforeand- after study of driver stopping propensity at red light camera intersections”, Accident Analysis & Prevention, 35(1), pp.111-120.

- Manual, H. S. (2010) AASHTO. Washington, DC, 529.

- Martinez, K. L. H. and Porter, B. E. (2006) “Characterizing red light runners following implementation of a photo enforcement program”, Accident Analysis & Prevention, 38(5), pp.862-870.

- McGee, H. W. and Eccles, K. A. (2003) “Impact of red light camera enforcement on crash experience – a synthesis of highway practice (NCHRP Synthesis 310)”, Transportation Research Board. Washington, DC.

- National Highway Traffic Safety Administration, NTHSA. (2009) “Fatality analysis reporting system (FARS)”. http://wwwfars.

- National Highway Traffic Safety Administration, NTHSA. (2009) “Traffic safety facts 2008 report.”

- Patel, R., Council, F. and Griffith, M. (2007) “Estimating safety benefits of shoulder rumble strips on two-lane rural highways in Minnesota: empirical Bayes observational before-and-after study” ,Transportation Research Record: Journal  of the Transportation Research Board, (2019), pp. 205-211. 

- Persaud, B. and Lyon, C. (2007) “Empirical Bayes before–after safety studies: lessons learned from two decades of experience and future directions” , Accident Analysis & Prevention, 39(3), pp.546-555.

- Poch, M. and Mannering, F. (1996) “Negative binomial analysis of intersection-accident frequencies.” Journal of Transportation Engineering, 122(2), pp.105-113.

- Porter, B. E. and Berry, T. D. (2001) “A nationwide survey of self-reported red light running: measuring prevalence, predictors, and perceived consequences”, Accident Analysis & Prevention, 33(6), pp.735-741

- Porter, B. E. and England, K. J. (2000) “Predicting red-light running behavior: a traffic safety study in three urban settings.” Journal of Safety Research, 31(1), pp.1-8.

- Porter, B. E., Luckett Jr, S. and Martinez, K. H. (2008) “The relationship between red light running and traffic volume: a research brief”, New Transportation Research Progress, 169.

- Retting, R. A. and Kyrychenko, S. Y. (2002) “Reductions in injury crashes associated with red light camera enforcement in Oxnard, California”, American Journal of Public Health, 92(11), pp.1822-1825.

- Retting, R. A., Chapline, J. F. and Williams, A. F. (2002) “Changes in crash risk following retiming of traffic signal change intervals”, Accident Analysis & Prevention, 34(2), pp.215- 220.

- 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, 4(1), 17-23.

- Retting, R. A., Ulmer, R. G. and Williams, A. F. (1999) “Prevalence and characteristics of red light running crashes in the United States”, Accident Analysis & Prevention, 31(6), pp.687- 694.

- Tegge, R. A., Jo, J. H. and Ouyang, Y. (2010) “Development and application of safety performance functions for Illinois”, Research Report ICT-10-066.