Closed Circuit Cameras

Live traffic cameras

MoDOT has  cameras installed along interstate highways and state routes in the St. Louis area. The video from these cameras is live, not recorded, and they help MoDOT’s Transportation Management Center operators monitor traffic flow. The operators can use the cameras to  identify potential congestion-creating incidents, such as crashes and stalled vehicles, and are able to direct the appropriate emergency response forces to those incidents. The cameras are also used to monitor the backup from road work zones. Operators use this information to convey messages to the public to detour motorists away or around these congestion points.

Video and photos from the cameras are only available in real time and are not stored. During crashes or incidents, cameras may not remain pointed at recovery efforts as operators continue to monitor the flow of traffic behind the incident. Since traffic is slow or stopped, the potential for additional crashes is increased during major incidents, and operators need to watch for those crashes and direct emergency response forces there, as well.

Camera views and videos are provided on MoDOT's Gateway Guide to offer drivers the opportunity to review and evaluate the flow of traffic on their projected route, and determine if they need to use an alternate route. Camera views are also provided to the local media through agreements to provide additional information in media traffic reporting efforts.

Signalized Intersection  Cameras

MoDOT uses cameras at signalized intersections solely for detecting the presence of vehicles in order to  adjust signal timing, as needed, based on traffic demand. They are cost-effective replacements for in-ground induction loops that are cut into the pavement.

The cameras are not focused on the drivers of vehicles, but instead on the vehicle as it moves towards the intersection.  Often, signals during rush periods are timed to help improve the flow of traffic.  Outside of those times, they may operate using detection.  When the vehicle enters the defined detection areas or "zones" within the camera's field of view, the camera's processor detects a change in the "zone." That alert is sent to the signal's controller (the computerized "brain" housed in a nearby metallic cabinet controlling the intersection's timing) that says a vehicle is requesting green time for its direction.  If there is not other, higher priority traffic, the signals are then changed accordingly to provide a green light for the incoming traffic at the intersection.