Published on 28 March, 2007
Cameras and zoom lenses from Rainbow are being used at freeway and intersection controls throughout the US by Florida-based Control Technologies who have chosen a modified version of Rainbow's 1/3" black and white 580 TV lines camera.
Based on data from the cameras, civic authorities are able to calibrate the cycle of signalised intersections and where necessary speed up vehicle exits from congested stretches of freeway. The aim is not only to ease movement on freeways but minimise congestion at known city bottlenecks. The sophisticated scene analysis approach used by Control Technologies is vastly superior to simple magnetic sensors and the techniques are being employed successfully in states including Texas, Florida, Georgia, Virginia, Washington DC and New York.
Control Technologies ensures that the client is able to monitors images using methods that are most appropriate to the particular environment and information needs. Images are fed to a video processor which may evaluate a traffic scene through pixel analysis, or the scene of free-flowing traffic might be assessed by the processor according to factors such as speed, volume on individual lanes or ‘headway time', this being the gap between one vehicle and the next. The system can also use five classifications when distinguishing between vehicles by length.
The Rainbow cameras are mounted on freeway gantries, luminaires and mast arms. They are being used in conjunction with Rainbow's 6.5~65mm F1.4 auto-iris zoom lenses.
Control Technologies has been active in the control and signal systems sector since 1980, manufacturing more than 25,000 traffic control enclosures. The company has agreements on territorial coverage with Oregon-based Kar-Gor Inc, and together the two companies dominate the traffic monitoring sector. Kar-Gor Inc is also a Rainbow customer for traffic camera assemblies.