Timed egress models are powerful analytical tools used to estimate the times required for occupants to evacuate a building during various emergency scenarios. Factors such as number of exits, exit capacities, number of occupants, distance to exits, occupant notification and occupant pre-movement times are considered. The decreased costs of computing technology and software developments allow timed egress to be used to effectively and efficiently model the dynamic behavior of a building egress system under varying conditions. Although these tools are now used theoretically, they could be applied to actual (as opposed to virtual) buildings to enhance life safety.
In theory, timed egress models optimize egress times based upon the shortest path to an exit; although this optimization mimics behavior, it does not produce a model of the most efficient exiting scenario possible. The application of timed egress models to actual buildings would facilitate the observation and direction of occupants during emergency conditions to optimize flows. In other terms, a "real-time" optimized exiting model would receive inputs and provide outputs based upon actual building conditions in order to enhance the survivability of building occupants. The model would then provide useful information and direction to evacuees and persons seeking rescue assistance based upon a comprehensive picture of the building conditions during evacuation. This could reduce total evacuation times, reduce hazard exposure and provide useful information to persons seeking rescue assistance and rescue personnel.
How do timed egress models consider accessibility? Although research concerning the ability of mobility impaired persons to egress has shown that the number of changes in direction can add considerably to evacuation times, current timed egress models do not completely address the varied abilities of mobility, visually and hearing impaired persons. A seemingly shorter escape route with more changes in direction can result in greater evacuation times than a less circuitous but longer route to an exit. Additionally, occupants often attempt to egress via the nearest exit even though significant bottlenecking and queuing may result in delays in egress times.
Another accessibility and egress life safety feature that might be of interest involves the ability to locate persons needing evacuation or rescue assistance. During emergency situations, individuals providing evacuation or rescue assistance need to quickly assess a situation and prioritize their responses accordingly. The ability to quickly locate individuals with special needs and assess their needs based upon emergency conditions within the building could be extremely helpful.
Wireless technologies could provide this ability to locate individuals, speed the response times of rescuers, provide communication links to these individuals and provide input to timed egress models to optimize egress for these persons. Additionally, the ability to locate disabled occupants quickly and make decisions about their safety based upon observed conditions could reduce occupant response times and reduce occupant travel times to a place of safety.
This communication feature would be particularly beneficial to individuals visiting large high-rise buildings or other facilities with which they were unfamiliar. When provided, two-way communications are typically managed at specific areas of evacuation assistance. A disadvantage of these fixed locations is they limit communications to and from specific locations within a building. Untethering these communication features with wireless communication capabilities would permit the communications to take place in locations other than designated areas of evacuation or rescue assistance.
Integrated Intelligent Egress and Communication System
The integration of aspects of an intelligent egress system with untethered communications would enable mobility, visually and hearing impaired persons to benefit from building intelligence that was targeted to their specific needs. Some of these communication features could be voice automated and integrated with the fire alarm system. Valuable time preceding the arrival of emergency responders could be utilized to proactively direct the targeted individuals with information that assists their decision-making processes. Some of this information could be based upon data processed by the fire alarm monitoring system. Voice synthesis would enable the fire alarm system to begin timely proactive communications to intended recipients before facility personnel or emergency responders initiated communication with these occupants. Essentially, occupants could begin to take corrective action that was more specific and responsive to actual building conditions.