For an Entire CITY!!!
Examples:
New York City: 7,660 (of a total of 12,460) signalized intersections are controlled by a central computer network and monitored by traffic management centers.
Toronto: 83% of its signals are controlled by the Main Traffic Signal System (MTSS). 15% also use the SCOOT (Split Cycle and Offset Optimization Technique), an adaptive signal control system.
Sydney: 3,400 traffic signals co-ordinated by the Sydney Co-ordinated Adaptive Traffic System (SCATS). Designed and developed by RTA, the system was first introduced in 1963 and progressively developed since then. By October 2010, SCATS was licensed to 33,200 intersections in 144 cities across 24 countries worldwide, including Singapore, Hong Kong, Dublin, Tehran and Minneapolis and Detroit.
Melbourne: 3,200 traffic lights across Victoria, including regional areas such as Geelong and Ballarat, using SCATS. Some 500 intersections also have tram and bus priority.
Adelaide: 580 sets of coordinated traffic lights throughout the metropolitan region managed by the Adelaide Coordinated Traffic Signal (ACTS) System.
I presume these systems are hardened with backups but my point was that we have created dependencies on complex tech.
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