# Applying Real-Time Travel Times to Estimate Fire Service Coverage Rate for High-Rise Buildings
## 2 Methods  
### Fire Apparatus Requirement  
Previous studies have shown that high-rise buildings have high fire risks [27; 28]. There are many combustibles in high-rise buildings which are prone to fire [29]. After a fire in a high-rise building, smoke can spread rapidly due to the stack effect. Due to the multiple floors, long evacuation distances, and densely populated people in high-rise buildings, it is difficult for people to escape in the case of fire [30; 31]. The property density of high-rise buildings is large, which is easy to cause great property loss after a fire. There are many high-rise buildings whose height far exceeds the working height of a fire truck. Therefore, it is difficult to put out the fire from the outside of the building. If firefighters carry out internal fire-fighting, they have to bear great pressure both physically and mentally. In essence, fire-fighting and the rescue of high-rise buildings have always been a difficult problem for fire departments worldwide. Fire apparatus requirements of high-rise buildings are directly determined by their firefighting strategies and tactics. National Fire Protection Association (NFPA) 1710 stipulated that an effective water flow rate of 1892 L/m from two handlines on the fire floor in high-rise buildings should be established [7]. The Chinese standard of GA/T 1191-2014 stipulated that aerial fire trucks, high-power water fire trucks, compressed air foam fire trucks, and air-supply fire trucks should be deployed during high-rise building fire [32]. [PERSON] et al. (2010) proposed a new concept of aerial fire-fightingwith rotorcraft vehicles in high-rise buildings [33]. [PERSON] et al. (2016) designed a moveable fire pump apparatus system with low-cost for fire suppression in high-rise buildings [34]. [PERSON] et al. (2016) proposed that the fire-fighting tactics of high-rise buildings should focus on internal fire-fighting and make good use of internal fire hydrants [9]. [PERSON] et al. (2017) invented a fire engine capable of launching fire-fighting missiles for high-rise building fire suppression [35]. [PERSON] et al. (2017) designed a hose-pump high-pressure system to deliver liquid fire extinguishing agents to firefighters in super high-rise buildings [36]. In general, the main fire-fighting strategy of high-rise buildings is to enter the building interior and use the fixed fire-fighting facilities (such as fire hydrant and automatic sprinkler system) to put out the fire. To ensure continuous water supply in the building, water fire trucks should be connected to pump adapters outside the building. During a long-term internal fire-fighting process, air respirators need to be used to assist firefighters in breathing, and air-supply fire trucks need to replenish air for air respirators. Foam fire trucks and water tower fire trucks should also be used to spray extinguishing agents on the outside of the building, and aerial ladder fire trucks and aerial platform fire trucks should be used to rescue people. In summary, water fire trucks, foam fire trucks, aerial fire trucks (water tower fire truck, aerial platform fire trucks, and aerial ladder fire trucks), and air-supply fire trucks should be deployed to the high-rise building fire scene. In the case of a high-rise building fire, fire apparatuses are often dispatched from multiple fire stations, and their arrival times will be varied. Obviously, the shorter the response time, the faster the fire can be put out. The objective value of a 5 min response time (including 1 min for initiating action and 4 min of travel time) was stipulated in the Chinese standard of GB51080-2015 [37]. Similar response time objective values were applied in previous studies and other countries' standards [7; 22; 38]. In this study, the objective value of a 5 min response time was also set. For each fire response process, the initiating action time is generally within 1 min, but the travel time varies greatly with the travel distance and traffic condition.