Office of Operations
21st Century Operations Using 21st Century Technologies Redundancies in the System

Entities have redundant communication systems that can be used during an evacuation.

For example, the New York Metropolitan Transportation Authority has redundant communication systems that proved useful during the 9/11 New York City terrorist attack. According to Saving City Lifelines: Lessons Learned in the 9/11 Terrorist Attacks: “The fact that the Metropolitan Transportation Authority could still communicate demonstrates the necessity of redundant communications capabilities. New York City Transit had multiple communications systems for both bus and subway systems, its own radio network, a six-wire system, an emergency booth communications system, a train dispatch system, and computer networks, all of which continued to function. New York City Transit also had the only telephone structure independent of Verizon. This capacity enabled New York City Transit to provide landline service to the New York Police Department command post and to emergency services in the field, while transit technicians assisted in the repair of the damaged communications systems.”

During the 2003 Great Lakes region blackout, several agencies had redundant power systems. The Detroit–Windsor Tunnel has quadruple redundancy, as it is serviced by four separate power feeds. According to Effects of Catastrophic Events on Transportation System Management and Operations: August 2003 Northeast Blackout Great Lakes Region, during the blackout, “the tunnel operator followed a pre-planned protocol in declaring a tunnel emergency and shutting down the facility. The tunnel cleared in less than 15 minutes. For the tunnel authority, the loss of communications was a challenge because the phones were dead. A backup battery and then a portable generator supported a radio system. They were able to notify the media and other agencies of their plans to close and, later, to re-open.”

According to the Effects of Catastrophic Events on Transportation System Management and Operations report, SMART had a generator providing power: “SMART’s operations center was fully functioning throughout the blackout, with dispatchers, phone lines, fax machines, e-mail, computers, and a Web site, which was updated with current information. Staff also maintained their radio system, used to communicate with drivers, for 10 or 12 hours. However, when they lost their radio communications system overnight, they decided not to run service on Friday except for critical paratransit customers, some of whom depend on SMART for life-saving dialysis treatment.”

February 7, 2006
Publication #FHWA–HOP-08-015