Emergency control system for traffic signals
US4223295A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 1978 |
| Grant date | Sep 16, 1980 |
| Priority date | — |
| Expiry date | Oct 18, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08G1/087
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An emergency control system for traffic signals in which a coded emergency signal transmitted from an emergency vehicle is picked up by a directional receiver associated with the traffic signals and a command emergency signal generated which activates a control unit by means of which the existing state of the traffic signals is sampled and the information stored after which the control unit switches control of the traffic signals from the main controller to the control unit which determines from the stored information the existing state of the traffic signals and the information from the receiver as to the direction of approach of the emergency vehicle, the correct sequence for placing the traffic signals in the proper state, the discontinuation of the emergency signal initiating the return of control of the traffic signals to the main controller by the control unit on the first amber light function output from the main controller.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.