Patent ID: 8362923

Claim:
A traffic signal system, comprising: a first traffic signal device, including a first communications device and a first plurality of lights; a second traffic signal device, including a second communications device and a second plurality of lights; said first traffic signal device running a first program for controlling said first plurality of lights in a particular sequence; said second traffic signal device running a second program for controlling said second plurality of lights in a particular sequence; said first traffic signal device and at least said second traffic device being part of a network; each of said first traffic signal device and said second traffic signal device being assigned a unique network address; and said first traffic signal device periodically querying said second traffic signal device using said second traffic signal device's unique network address; and the traffic signal system entering a cautionary state if at least one of: a) at least one traffic signal device on the network fails to respond to a query; and b) fails to query another traffic signal device on the network after a predetermined time period.