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Stair Evacuation of People with Mobility Impairments



Erica D. Kuligowski, Richard Peacock, Bryan Hoskins, Emily Wiess


The time that it takes a population to reach safety when descending a stairwell during building evacuations is typically described by measureable engineering variables. These engineering variables include stairwell geometry, speed, density, and pre-evacuation delay. In turn, engineering models of building evacuation use these variables to predict the performance of egress systems for building design, emergency planning, and/or event reconstruction. The buildings populations comprised a diverse array of older adults and disabled residents descending the stairwells by the following methods: self-evacuation without assistance, assistance using a cane, assistance from another occupant or firefighter, or assistance using a stair chair. Movement data of these specific groups was compared and contrasted with other data collected on mobility-impaired individuals. In the current study, the National Institute of Standards and Technology observed overall average speeds of (0.31 ± 0.16) m/s (with individual speeds ranging from [0.07 to 0.91] m/s), which in some cases, approximate the speeds of disabled people and older adults found in earlier studies, and in other cases is slower than previous studies. Slower speeds in this case may have resulted from observing a wider variety of mobility impairments (since one of the buildings observed was an assisted-living facility) and from evacuation assistance provided by untrained populations. These data provide an adequate confirmation of exiting literature values typically used for disabled movement speeds in addition to updated values for future analyses.
Fire and Materials


Aging, building design, disabled, egress, evacuation, fire drills, fire safety, mobility


Kuligowski, E. , Peacock, R. , Hoskins, B. and Wiess, E. (2014), Stair Evacuation of People with Mobility Impairments, Fire and Materials, [online], (Accessed June 13, 2024)


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Created March 2, 2014, Updated October 12, 2021