Citation

Sime JD. Safety Sci. 2001; 38(2): 109-125.

Copyright

(Copyright © 2001, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

This paper contrasts the physically deterministic travel/flow model of behaviour in fires, represented by prescriptive fire codes and performance-based fire engineering, with an occupant response model. An occupant response shelter escape time (ORSET) model is advocated as a framework unifying aspects of psychology, architecture, engineering and facilities management. Important to this are the concepts of occupancy, occupants and occupant locations, allied to visual and sensory access/exposure, used to define people's knowledge of their surroundings. The paper provides a generic outline of ORSET, expressed in terms of occupancy risk criteria: occupancy population and activity profiles, a pre-movement index, visual access/wayfinding design/index and means of escape. These serve as inputs to the appraisal and measurement of occupant response pre-movement and movement, wayfinding patterns of behaviour and corresponding safety factor adjustments to minimum shelter and/or travel/flow time calculations. Attention is drawn to the importance of researching and modelling occupant starting time distributions, staggered phases of response, arrival and flow rates at alternative exits. The available safe escape time needs to be greater than ORSET. The paper discusses the scope, implications, development and applications of the model, concluding with related recommendations.