Frequently Asked Questions

Q:  What are traffic enforcement cameras? 

A:  Traffic enforcement cameras are installed on dangerous roadways and at intersections where accidents, injuries and fatalities are caused by speeding and red light running.  These cameras photograph vehicles whose drivers have entered an intersection after the traffic signal has turned red or those exceeding the speed limit in enforced areas.

Q:  How often do drivers run red lights?

A:  A study conducted over several months at a busy intersection in Arlington County, Virginia, indicates that motorists frequently run red lights.  On average, a motorist ran a red light every 12 minutes.  During peek travel times, red light running is more frequent, at some periods recording a violation every 5 minutes.

Q:  How do speed cameras work?

The speed system measures a vehicles speed as it approaches an enforced area.  If the vehicle is exceeding a predetermined amount set by the City, the cameras capture images of the vehicle along with data such as the time of day, speed of vehicle, day of the week, etc.

Q:  How do red light cameras work?

A:  The red light camera system is connected to the traffic signal control box and continuously monitors the status of the traffic signal.  When the traffic light turns red, the system is ready to capture pictures of a vehicle running the red light.  In-ground loop sensors or aboveground devices measure the speed and distance of the vehicle as it approaches the red traffic signal.  When the system detects that the light is red and the vehicle is not stopping, a set of signals are generated that produce the violation images. 

Q:  Isn’t Conventional Police Enforcement Sufficient?

A:  Enforcing traffic laws in dense urban areas by traditional means poses special difficulties for police, who in most cases must follow a violation vehicle through a red light to stop it.  This can endanger motorists and pedestrians as well as officers, and police cannot be everywhere at one time.  Communities do not have the resources to allow police to patrol intersections and roadways as often as needed to ticket all motorists who speed or run red lights.  The cameras allow police to focus on other enforcement areas.

Q:  What safety benefits do traffic enforcement cameras provide?

A:  Red light camera systems have been shown to reduce red light violations and intersection crashes.  A recent Institute of Highway Safety study of a program in Oxnard, California, shows that red light running violations dropped by a total of 42 percent after cameras were installed at nine intersections.  Another study showed violations declined about 40 percent in Fairfax, Virginia, after one year of camera enforcement.  Often times, a “spill-over” effect results from automated enforcement – other intersections not monitored by automated enforcement realize a decrease in violations and accidents because of the presence of enforcement in the city.

Q:  What if I am in the intersection when the light turns red? 

A.  The camera is activated and enforcement begins when the signal light turns red.  Once the signal light turns green, the system automatically turns off and enforcement ends.  The system is designed so that it can only capture an image during the red light phase - it does not take an image during the yellow or green light phase. 

Q.  When a violation occurs, who receives the citation?
A.  Both speed and red light citations are mailed to the registered owner of the vehicle following review of image data by trained City of Chattanooga Police Officers.

Q:  What if the registered owner was not driving the car?

A:  The registered owner may rebut the notice regarding traffic signal violation by 1) filing a notarized statement with the court identifying the name and address of the operator of the vehicle at the time of the alleged violation, or 2) testifying under oath in court that he or she was not the operator at the time of the alleged violation, or 3) providing a certified copy of a police report showing the vehicle was stolen prior to the alleged violation.

Q:  What information is included on the violation notice?

A:  The violation notice will have multiple digital images of the vehicle running the red light or speeding in an enforced area.  The violation notice will also record information concerning the speed of the vehicle, the length of time the yellow light was displayed for red light violations, the length of time the light was red before the violation occurred, time of day, and other pertinent data.  The violation notice will also provide information on paying the fine or appealing the notice. 

Q:  What is the penalty?  

A:  The penalty for speeding or red light running using automated traffic cameras is $50.  No points will be assessed on the driver’s license and no information is sent to the State.  Citations are mailed to the registered owner of the vehicle.

Q:  Can I expect a camera at every intersection or roadway in the future?

A:  No.  Intersections and roadways will be selected based on traffic crash data.  Potential locations will be reviewed to determine if there is an engineering solution to the crash problem.  Automated traffic cameras will be considered only when there is a high incidence of traffic crashes and there is no apparent engineering solution. 

Q:  Where are cameras currently being used?

A:  Photo red light enforcement has been used in the United States for more than 15 years and in Europe for nearly 30 years.  Systems are used in the United States in more than 160 communities in 25 states, including Tennessee, Georgia, Arizona, California, Maryland, and Ohio.  Studies indicate a substantial decrease in traffic crashes at intersections and on roadways where traffic enforcement cameras are installed.  Organizations such as the National Highway Traffic Safety Administration (NHTSA) and the Insurance Institute for Highway Safety have information and web sites available on this subject.