MODELLING THE EVACUATION OF ELDERLY LOCOMOTION IMPAIRED OCCUPANTS FROM BUILDINGS

This project involves developing a realistic representation of the elderly and locomotion impaired within evacuation models such as buildingEXODUS.

Within minutes of ignition a severe building fire has the capability of overpowering occupants through a deadly cocktail of toxic gases and intense heat.  In order to survive occupants must quickly evacuate the building to an area of safety.  Evacuation models offer building designers a means of testing evacuation plans and provisions that expedite safe egress.  However, to date evacuation models have poorly represented a section of the population that has great difficulty in evacuating.  This research attempts to remedy this through better representing the elderly and locomotion impaired within evacuation models.

According to a recent survey approximately 12% of the British population (based on a survey in Northern Ireland) have some form of disability.  The types of disabilities are varied for example, angina, partial sightedness, deafness and arthritis. Of those people with disabilities 50% have difficulties with locomotion of which the vast majority are aged.

Traditional building design analysis techniques have either ignored people with disabilities or greatly simplified their representation.  Recently evacuation models have attempted to represent locomotion impairments through an appropriate performance penalty, which is imposed upon disabled occupants.  However, this method makes no attempt to model the complex human behaviour that accompanies a disability.  A typical behaviour for the elderly with locomotion difficulties is that they suffer from fatigue and need to take frequent periods of rest.

buildingEXODUS is a sophisticated evacuation model being developed by FSEG that has the capability of representing individual people and their abilities.  A prototype version of the buildingEXODUS evacuation model is currently being developed that better represents the behavior of elderly locomotion impaired occupants.  Within this prototype, occupants may stop and recover when they feel they are reaching the limits of their physical abilities.  The need to recover precipitates a complex judgement based on the proximity of suitable rest aids, i.e. walls, chairs or people, and the requirement to choose a relatively safe area that reduces the chance of obstructing others.  Upon finding a suitable site for recovery, the occupant would recover and then resume their evacuation.   The net result is that their behaviour is explicitly modelled, as shown in Figure 1.  This behaviour is based on data collected from movement experiments involving the elderly and mobility impaired.
 

This research has developed a more realistic evacuation model with which designers and architects can assess the safety of buildings for elderly locomotion impaired occupants.

For more information about evacuation modelling and the EXODUS software visit the EXODUS Web Pages. For a complete listing of EXODUS and evacuation publications visit the FSEG Publications pages.