The control of traffic signals is distributed between the intersection controller (microprocessor) and the central computer.  The microprocessor at the intersection controls the red, yellow and green colors, not the central computer.  Therefore, if communication is lost between the two, the intersection continues to operate normally.  The local controller can collect information about color displays, traffic volumes or equipment malfunctions and send this information back to the central computer within one second.

The system can scan all 1276 traffic signals within 12 seconds for the status of equipment failures and activate an alarm upon detection of a failure.  If the equipment failure is related to a physical hardware component failure, it cannot be repaired from the central computer and a repair technician must be dispatched.

If traffic signal timing change is required, shorter or longer green times can be changed from the traffic management center.  However, if a roadside camera is not available at an intersection, an engineer or technician will need to visit the location and observe that the new green times are optimal.