Evacuation Using Familiar Paths

Created with software version 2020.1

To follow along with this tutorial, download the assign-familiar-exit-doors.pth model here.

1. Introduction

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 2016). 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. We will demonstrate this technique with a simple example.

2. Familiar Paths 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.

path scrn familiar geometry
Figure 1. A room with a familiar Entry and two Exits

To do this, we define two Behaviors. For the first, 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.

path ui dialog exits entry behavior
Figure 2. Select the exit door to be used by the Use Entry behavior

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. This can be seen in Figure 3.

path ui dialog behavior distribution
Figure 3. Add occupants using a distribution of behaviors

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 (Figure 4), 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.

path scrn familiar results
Figure 4. Results showing blue occupants exiting the familiar Entry and red occupants exiting the two Exits

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3. Bibliography

SFPE. 2016. SFPE Handbook of Fire Protection Engineering. 5th ed. Springer-Verlag New York. https://www.springer.com/us/book/9781493925643.