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49 present, and dirt/debris build up. (For example, locating a com- Twenty-four tunnels responded to what is an acceptable mercially available pull station system for the roadway tunnel response time for a fire emergency, and answers ranged from application that is reliable over a long time period has proven difficult). 3 to 20 min. All seven VDOT tunnels considered 10 to 15 min acceptable, whereas all nine Oregon DOT tunnels considered Many of the U.S. tunnels (22 of 29) would consider a fire 20 min to be an acceptable response time. The lighting and event to be similar to a seismic event for design purposes. emergency communication systems were often not designed to survive major fire events (17 of 30). One-half of the Most international agencies, four of the seven reporting, 30 tunnels reported that they were inclined to actively screen have their own standard for tunnel design and for fire rating. or otherwise monitor truck cargoes entering a tunnel without All five international respondents stated that the most com- disrupting the traffic flow as a prevention method. Of the mon guidance/standards used by designers to address the eight that responded with the most common fire or life safety fire design issues for new and retrofitted tunnels were either equipment planned for repair or replacement, all responded domestic regulation, European Union, or PIARC. In Canada with tunnel ventilation, standpipes, and communication. they use NFPA 502. Four of seven responded that designers The next most common choice was emergency lighting (six are usually given only the fire size, whereas three are provid- responses). ing the fire curve. Two of the six international agencies to respond reported that designers usually implement only secu- The average of the 20 U.S. tunnels that provided a numer- rity, followed by two respondents noting that they implement ical life expectancy was 105 years. VDOT noted that for its security and blast design. seven tunnels their "design life is 50 years, however, life expectancy typically exceeds 100 years." The Chesapeake One-half of the international agencies reported that the Bay Bridge and Tunnels stated for both of their tunnels that Authority Having Jurisdiction is usually the fire department. it "depends on the amount of maintenance performed." All seven international agencies responding reported apply- ing a risk assessment approach for fire engineering. This Most U.S. agencies (19 of 31, 61%) reported on the need is probably the most obvious difference between the U.S. for additional training tools for operators to manage a fire and international approaches. Five of the seven respondents using tunnel fire/systems simulators. reported having an emergency response plan in place. Outside of the United States, and excluding Korea's "aver- Of the six international agencies responding on which age from 280 tunnels," the average age is approximately agency has the role of incident commander, two reported the 16 years (built about 1994). All seven international agencies fire department and two that it is in cooperation with the fire reported that their tunnels are under 24-h supervision. (Please department. Four of six international tunnel agencies reported note that there are many unmanned tunnels all over the world that they would consider protection of the tunnel with the and the above number does not reflect all of the existing tun- fixed fire suppression system (sprinkler system) if proven nels.) Six of the seven international agencies stated that their effective. Most of the agencies (four of six) have identified tunnels run uni-directional during normal traffic operation. gaps in research and design for tunnel fire safety or fire detec- Four of the six international tunnels reported that their tunnels tion and protection. One area needing improvement, accord- never operate in bi-directional mode. The rest normally do ing to one agency, is "Real world experience in the use of operate in bi-directional mode. As for what types of vehicles deluge." Most of the international tunnels (five of six) would use the tunnel, five of seven tunnels reported HGVs and four not consider a fire event to be similar to a seismic event for reported gasoline tankers (freely). design purposes. Internationally, there was a broad spectrum of tunnel life expectancy. Three of the seven tunnels chose 100 years and MAINTENANCE, REPAIR, AND REHABILITATION OF THE FIRE MANAGEMENT SYSTEMS two chose 50 to 100 years. The other two agencies reported 200 years and 80 years. The average tunnel age as given by the 32 U.S. tunnels was approximately 54 years (built around 1956). Most tunnels are Two of the six international tunnel agencies reported that under 24 h supervision (21 of 32 tunnels reported). The major- 10 to 15 min is an acceptable response time for reaching a fire ity of the tunnels reported that the normal traffic operation is event. The remaining four reported 2 to 10 min. Five of the uni-directional (28 of 32). Thirty-four percent (11 of these 32) six agencies reported that the lighting and emergency com- reported that their tunnel operates in bi-directional mode only munications systems were designed to survive major fire during construction/maintenance in the other tube and 16 never events most of the time. run in bi-directional mode. Eight U.S. tunnels allow gaso- line tankers to run freely and four tunnels can be used by Five of the six tunnels do not actively screen or otherwise gasoline tankers when supervised and during special times monitor truck cargoes entering the tunnel without disrupting (schedule or tunnel closing). the traffic flow.