An Evacuation Decision Model based on perceived risk, social influence and behavioural uncertainty

• An Evacuation Decision Model predicting pre-evacuation behaviour is introduced.
• The model simulates the probability of evacuees’ behavioural state.
• Environmental and social cues affect evacuees’ perceived risk.
• A formulation to calibrate the proposed model is provided.

The behaviour of people in the first stage of an evacuation can have a significant impact on the time required to reach a safe place. This behaviour is known in literature as pre-evacuation behaviour and it has been studied for many different evacuating scenarios. Despite the large number of studies, the representation of this behaviour is often oversimplified in most of the existing evacuation models. This paper aims to introduce a novel Evacuation Decision Model, allowing predicting the pre-evacuation state of an evacuee among three possible states (normal, investigation and evacuation) considering perceived risk for an evacuation scenario. The proposed model assumes that evacuees’ perceived risk is affected by several environmental and social cues as well as by demographics and personal characteristics of evacuees. The concept of behavioural uncertainty is also included in the model and a formulation to calibrate the proposed model using a likelihood function is then provided.