Enforcing Traffic Laws with Red-Light and Speed Cameras

By Jonathon Bates and Shelly Oren | Vol . 28, No. 26 | July 2020


Automated enforcement with red-light cameras and speed cameras allow state and local governments and law enforcement agencies to remotely capture images of drivers violating traffic laws. Even though such tools usually decrease serious traffic crashes, they are not always without controversy. State responses range from authorizing local governments to use automated enforcement to limiting or banning it altogether.

Red-light cameras link to traffic signals and monitor the green, yellow and red phases of traffic lights. After the light turns red, the camera takes a picture before the vehicle enters the intersection and again when the vehicle is in the intersection. Both photos must show the signal in the red phase in order to issue a citation. Speed cameras use radar, laser or detectors embedded in the road to measure a vehicle’s speed. If a vehicle is traveling faster than the posted speed limit, the camera will record its speed and license plate, along with the date, time and location. A citation will be issued—either to the registered owner or the driver, depending on the enabling legislation—if the driver exceeded the speed limit, typically by more than 10 or 11 mph, according to Insurance Institute for Highway Safety (IIHS).

Studies evaluating the effectiveness of automated enforcement generally show a positive effect on traffic safety. An IIHS study found that red-light cameras reduced the fatal crash rate in large cities by 21% and the rate of fatal crashes at signalized intersections in general by 14%. A 2016 IIHS study found that the likelihood of a driver exceeding the speed limit by more than 10 mph on roads with cameras decreased by 62%. However, the administration of automated enforcement programs can cause concerns. One commonly cited reason for community opposition is that such programs are perceived as revenue-generating tools. A coalition of traffic safety groups developed a checklist for red-light camera programs that emphasizes transparency and implementation based on safety concerns.

State Action

At least 33 states and the District of Columbia have laws addressing a variety of issues related to automated enforcement, including to authorize or prohibit it. State laws generally establish guidelines for municipalities, such as limiting the use of cameras to certain cities or authorizing their use statewide.

Recent trends show fewer governments are operating red-light and speed cameras. In Missouri, the state’s Supreme Court ruled in 2015 that red-light and speed cameras were unconstitutional. Other state laws explicitly prohibit automated enforcement. Maine, Mississippi, New Hampshire, South Carolina, Texas and West Virginia prohibit both red-light cameras and speed cameras. Montana and South Dakota prohibit red-light cameras, and New Jersey and Wisconsin do not allow speed cameras.

Cameras are used in highway work zones in Illinois, Maryland, Oregon and Pennsylvania. Pennsylvania enacted legislation in 2018 (SB 172) that established a five-year pilot program for automated speed enforcement cameras in highway work zones, which began in March 2020. Drivers going 11 mph or more over the posted speed limit in work zones when highway workers are present will be given a warning after their first offense, fined $75 after their second offense and $150 after their third offense.

In 2019, at least four states—Hawaii, Maryland, New York and Texas—enacted five pieces of legislation related to automated enforcement. Hawaii (AB 663) established a red-light running committee to provide recommendations for automated enforcement programs in Honolulu, Maui, Kauai and Hawaii counties. Maryland (HB 187) increased the number of authorized speed monitoring systems for a certain road in Prince George’s County. The new law expanded on 2018 legislation (HB 175), which allowed the county to install one speed camera at a specific intersection.

In New York, two bills were approved in 2019. One law (AB 951) authorized a speed camera demonstration program in school zones in the city of Buffalo. Drivers traveling over 10 mph above the posted speed limit will be fined. The fines are capped at $50 for each violation. Additionally, the other new law (AB 6449) expanded the speed camera program in the city of New York. Specifically, the number of authorized school zones was increased from 140 to 750. The law also extended the hours in which cameras could be operated to between 6 a.m. and 10 p.m. Previously, cameras could only be operated during a school’s active hours. By doing so, this expansion has made New York City’s automated enforcement program the largest in the nation, according to a New York Times article.

Texas (HB 1631) prohibited localities from using red-light cameras, an idea lawmakers have considered since 2007. In signing the new law, Governor Greg Abbott cited constitutional issues with cameras as drivers are unable to confront their accuser in court. However, communities with existing contracts are allowed to continue operating cameras for the time being.

Federal Action

Federal surface transportation programs are generally governed by the Fixing America’s Surface Transportation (FAST) Act. This, $305 billion, five-year bill was enacted in 2015 and expires on Oct. 1, 2020. The legislation prohibits states from using federal funds from the Highway Safety Improvement Program and the Highway Safety Grant Program to purchase, operate or maintain automated traffic enforcement cameras, except for those located in school zones. Secondly, states with automated enforcement systems are required to conduct a biennial survey—2020 surveys can be found here. It must include a list of automated enforcement systems in the state; data to measure transparency, accountability and safety; and a comparison of their systems to Department of Transportation guidelines on automated red-light-running and speed enforcement programs. However, the recently introduced INVEST Act by the House Transportation and Infrastructure Committee would relax some of these requirements, though it is unclear if the provisions will be enacted by Congress.