Abstract: An intersection monitor for remote monitoring of traffic intersection controllers. A central computer is connected through the public telephone system to intersection monitors, one of which is located at each remote intersection. The remote intersection monitor monitors the operation of the intersection controllers and related equipment and, upon detecting the malfuntions of a preselected priority, report such malfunctions by placing calls through the public telephone system to the central computer. The central computer, by placing a call on the telephone system, also may interrogate each of the remote intersection monitors and transfer operating instructions to each monitor. Vehicle and pedestrian detectors also are monitored by each remote intersection monitor and unusual activity or inactivity of such detectors is reported by the remote intersection monitor to the central computer.

Abstract: The status of the traffic signals is repeatedly monitored. A visual display is presented of the spatial arrangement of the traffic signals in the system. The currently monitored status of the traffic signals is repeatedly represented on the display, spatially coordinated with the display of the respective traffic signals. A plurality of previously monitored statuses is also repeatedly represented on the display, spatially coordinated with the respective traffic signals and a traffic speed progression representation therebetween. The display distinguishes between through green and local green traffic signal status. A comparison is made of the currently monitored status of a traffic signal under consideration with the previously monitored status of the adjacent traffic signals as the latter arrives at the traffic signal under consideration and a separately distinguishable mark represents a discrepancy in the comparison when the previously monitored status is through green.

Abstract: A power supply particularly for use with a traffic control system has a voltage monitoring and control system which continually monitors the line voltage fed to the traffic control system and automatically turns off the power when the voltage drops below a predetermined minimum for a predetermined time period or provides a warning signal should the voltage drop below a higher second predetermined minimum for a predetermined time interval. In the event that the voltage returns to a predetermined acceptable value for a predetermined time period, the power is automatically restored and the warning signal discontinued. The monitoring system includes sensors operative in response to each of the control parameters which operate in conjunction with logical control circuitry to effect the desired controls.

Abstract: A device used in the control of automobile traffic signal systems for maintaining a local time reference during periods when the a.c. power is interrupted. An accurate oscillator such as a crystal controlled oscillator is used to provide a local time reference during power interruptions. The device maintains a local clock in synchronism with the a.c. power when the power is present and maintains the time reference in synchronism with the crystal oscillator during those periods when the a.c. power is absent. Pulse trains at different rates generated in synchronism with the oscillator are combined to achieve these objects.

Abstract: A synchronization device for the control of an automobile traffic signal in synchronization with other traffic signals in the system. A present time clock in the device operates from the local alternating current power source. The synchronization device calculates the time difference between the present time and a daily re-synchronization time, divides that time difference by the length of the operating cycle of traffic signal, and generates a synchronization pulse whenever the residue of the division is zero. An offset or time-delay is added to the synchronization pulse and the traffic signal is operated in response to the delayed synchronization pulse so as to operate with the desired time delay in coordination with the other signals in the system.

Abstract: A housing for traffic signal lamps employs modular building block units with a minimum number of different components, which can be combined together to form a variety of configurations. A basic half section unit is used to form the individual lamp housings. This half section unit is in the form of a tray having an internal rib structure and an external rib on the front surface for stiffening, a pair of such units being joined together to form a container for a traffic lamp. An aperture is formed in the front wall of the container for passing the light from the lamp, there being a door wth a mating aperture formed therein removably latched to a hinge pin structure formed on the front wall of the container. This hinge pin structure and the latching mechanism on the door are arranged to permit either right or left hand opening of the door.