Lifts for evacuation - Human behaviour considerations
The concept of using lifts for evacuation form high rise buildings in fires and other emergency events is gaining momentum around the world, with the recent inclusion of clauses in the International Building Code(IBC) to regulate the design of such lifts and a growing number of buildings, incorporation this new technology. To predict the time that a building will take to be fully evacuated in an emergency and to design lift systems capable of dealing with the demand, building designers need an understanding of the likely exiting behaviour of occupants.
Due to the inherent difficulties of carrying out research in human behaviour, a number of approaches have been used to try to address these issues. These include carrying out a number of survey’s and comparing results to data from past fire events where the lifts have been used of evacuation The results from this work suggest that the split of occupants using the stairs or lifts to evacuate is governed predominantly by floor level of the occupant. In addition, it has been shown that it is unreasonable to expect that occupants will wait indefinitely for a lift to arrive in an emergency situation if they are given no information about the likely waiting time. The drop-off in the percentage of occupants that will continue to wait for a lift with increasing waiting time also appears to be dependent on floor height.
It is expected that these results will allow building designers to make more realistic assumptions when designing evacuation strategies incorporating lifts. In addition, it is hoped that a better understanding of the reservations that building users may have about using lifts for evacuation in emergency situations will allow occupant training programmes to be developed to address these concerns.