Method and apparatus for displaying the status of a system of traffic signals

A method for graphically illustrating improper coordination of an arterial traffic control system having a plurality of traffic signals, the method comprising the steps of:

• repeatedly monitoring the statuses of the traffic signals;
• presenting a visual display of the current statuses of the traffic signals in the system;
• storing the monitored statuses of the traffic signals;
• comparing a currently monitored status of each traffic signal with a previously monitored status representative of the transit time from an adjacent traffic signal at a designed progression speed;
• and
• representing on the display a mark spatially coordinated with the display of respective traffic signal when there is a discrepancy in the comparison.

In a traffic control system having intersection traffic signal controllers and an arterial master progression coordinator in part controlling the intersection traffic signal controllers, apparatus for displaying the status of traffic signals comprising:

• means for monitoring the status of the traffic signals;
• a visual display device;
• means for presenting on the display device a spatial arrangement of the traffic signals in the system;
• means for repeatedly representing on the display the currently monitored status of the traffic signals spatially coordinated with the display of the respective traffic signals;
• and
• means for repeatedly representing on the display a plurality of previously monitored statuses spatially coordinated with the respective traffic signals and a traffic speed representation between the respective traffic signals.

A method of displaying the status of a system of traffic signals comprising the steps of:

• presenting a visual display of the spatial arrangement of the traffic signals along an arterial line in the system;
• presenting a display band of traffic signal statuses parallel to the arterial line;
• requesting the current status from each traffic signal at each sampling interval;
• entering the current status data from each traffic signal into the display band adjacent to the presentation of such traffic signal on the arterial line at each sampling interval;
• and
• shifting the previous status data in the display band a predetermined distance in the direction of traffic flow at each sampling interval.