Enforcement programs - automated speed & red light running

Automated speed enforcement (ASE) and red light running (RLR) enforcement use cameras to detect traffic law infractions and provide photo or video documentation of the vehicle or driver violating the law. These automated programs enforce speed limits and traffic signal compliance to improve safety and reduce congestion.

Key characteristics




WSDOT regions

Other names

  • Red light cameras
  • Speed cameras
  • Automated citations

Strategy description

Law enforcement officers cannot be at every signalized intersection or along every corridor or primary roadway to ensure safe driver behavior. However, technology offers a solution through automated enforcement programs that can improve safety and reduce congestion. Two of the most common automated enforcement programs are automated speed enforcement (ASE) and red light running (RLR) cameras that detect traffic law infractions and provide photo documentation of the vehicle or driver violating the law.

Red light running and speeding are significant traffic safety issues. Collisions related to red light running result in approximately 700 deaths each year in the United States (1). Speeding is cited as a contributor in more than 9,000 roadway deaths each year (2).

Before implementing an automated enforcement program, traffic engineers must ensure traffic signal timing and posted speed limits follow established guidelines and agency policies.

A basic automated enforcement setup follows this process:

  • Cameras take photos (and in some cases, video) of any vehicle violating the signal or speed limit (e.g., entering the intersection after the light has turned red, or driving faster than the posted speed limit). 
  • Photos/videos are communicated to a centralized review location - typically a local police department.
  • Police review the violation for accuracy, then send a ticket to the registered owner of the vehicle. It typically includes a photo of the violation, and sometimes a link to the video.
  • The registered vehicle owner pays the fine or appears in court.

When to use this strategy

Automated enforcement programs like ASE and RLR make sense for situations where standard safety treatments have not reduced the number of violations, and especially where red light running and speeding have contributed to traffic collisions.

Strategy benefits:

  • Reduces the number of speed limit and red light running violations
  • At signalized intersections, reduces the number of collisions caused by red light running

Note: Automated RLR can sometimes lead to an increase in rear-end collisions, though these incidents typically do not result in severe injuries. This occurs because some drivers will overreact to the automated enforcement system by stopping when the light turns yellow.

Along corridors with speed enforcement, reduces the number and severity of all collision types for two reasons:

  • At slower speeds, all motorists have more time to react to other road users
  • When collisions do occur, slower speeds result in lower severity


What you need in order to implement

Policy needs:

  • Legislation (e.g., state law, city/county ordinances) that allows automated enforcement. Some of these are limited to particular situations (e.g., speed enforcement only in school zones and/or highway work zones).

Coordination needs:

  • Engineers who operate the signals and establish the posted speed limits.
  • Law enforcement agencies and officers who will review automated enforcement citations.
  • Department of Motor Vehicles to receive vehicle registration information and owner addresses.
  • Local judicial system to educate judges and prosecutors on the policy and the systems.

Equipment needs:

  • Automated enforcement cameras (photo and/or video) and communication devices like cellular to provide information to law enforcement.
  • Office back-end process software to review violations and send out tickets.

Maintenance needs:

  • Calibration and consistent checks of all equipment.
  • Regular maintenance of signal timing.
  • Evaluation of vehicle operating speeds are needed on a regular basis.

Agency resources needs:

  • Staff dedicated to addressing policy questions from governing bodies and citizen concerns, and to coordinate with law enforcement and policy makers.

Learn more about this strategy

Federal Highway Administration (FHWA) Office of Safety Red Light Running web page.

Federal Highway Administration (FHWA) Red Light Camera Systems Operational Guidelines (PDF).

National Highway Traffic Safety Administration (NHTSA) Speed Enforcement Camera Systems Operational Guidelines (PDF).

National Cooperative Highway Research Program (NCHRP) Report 731, Guidelines for Timing Yellow and All-Red Intervals at Signalized Intersections.

Works cited:

(1) Fatality Analysis Reporting System (FARS) data via FHWA Office of Safety Intersection Safety.

(2) FHWA Office of Safety Speed Management Safety.

About key characteristics

Location notes:

State law and local ordinances determine whether automated enforcement is legal. RLR enforcement can be used at signalized intersections. ASE can be used along any roadway with an established posted speed limit.

Cost notes:

Implementing ASE and RLR enforcement require a moderate cost investment. Cameras and communication devices are required at each traffic signal. Officer time is also needed to review each photo/video and approve citations.

Technology notes:

The technology needed for ASE and RLR enforcement is moderate. Cameras must be sophisticated enough to capture license plate numbers and communication devices are required at each signal to send information to the reviewing officers.

Collaboration notes:

Significant collaboration is needed to implement ASE and RLR enforcement. Engineers must collaborate with local law enforcement, local public works (if on a non-State-owned roadway), and judicial system for a successful program.

Need or issue this strategy addresses