During an evacuation, “… familiar entry routes are more likely to be used for evacuation than egress routes that have never been experienced before. Consequently, routes that are being counted on to “drain” the building of its occupants may be disregarded in an actual evacuation.” (SFPE Handbook of Fire Protection Engineering). One way to represent this is to assign some fraction of occupants to use an exit door (or doors) with which they are familiar, while other occupants can use any exit.
Let us demonstrate with a simple example. In Figure 1 we show a room that has one familiar Entry and two Exits. The room is 10×10 m and we will place 200 occupants in the room. We want 70% of the occupants to evacuate using the Entry and 30% using either of the two Exits.
To do this, we define two Behaviors. For the first behavior, we edit the Exits and choose only the Entry door. For the second, we edit the exits and choose both Exit 1 and Exit 2.
Now we right-click on the room and select Add Occupants. In the Add Occupants dialog, we click on the Behavior and assign 70% to Use Entry and 30% to Use Exit 1 or 2, Figure 3.
Finally, we assign a different color to the occupants using the exits by right-clicking on the Use Exit 1 or 2 behavior and clicking Select Referencing Objects. We change the color of those occupants to red.
When we view the results, we see that the blue occupants (140 persons) exit using the familiar Entry and the red occupants (60 persons) use either of the two Exits.
A couple of comments:
- If you are working with a model where you have already created the occupants, you can right-click the Occupant Group and select Properties to assign a distribution of behaviors.
- Any behavior can have any combination of exits. The default behavior allows the occupants to use any exit.
Download Pathfinder Modelassign-familiar-exit-doors.pth
Comments or Questions
This post was written by Daniel Swenson. For comments or questions, send email to firstname.lastname@example.org.