Fundamental Diagram Customization in Pathfinder

Posted: May 14th, 2015 in News

Evacuation engineers are responsible for understanding the accuracy of their calculated results by studying their simulation model. Some engineering groups may place a high priority on specific research or accept standards proposed by industry pundits. Across different parts of the world, pedestrian movement characteristics may also depend on cultural behavior. One key is the fundamental diagram, which defines occupant flow as a relationship between walking speed and occupant density. Pathfinder (Version 2015.1.0515) allows engineers to define a fundamental diagram used in their simulation to provide an accurate understanding of their results.

Figure 1. User modifiable speed-density profiles for occupant movement enables custom fundamental diagrams.
Figure 1. User modifiable speed-density profiles for occupant movement enables custom fundamental diagrams.

By default, Pathfinder uses the fundamental diagram from SFPE to provide the user with a speed-density relationship that has wide acceptance and conservative estimations. However, there are other proposed fundamental diagrams. With the proper data points from a given diagram, a Pathfinder agent profile can be configured to model any speed-density curve, as seen in Figure 1. These profiles can be saved along with other occupant parameters for easy reuse across multiple projects.

Figure 2. Experimental data provides validation for Pathfinder’s custom fundamental diagram feature.
Figure 2. Experimental data provides validation for Pathfinder’s custom fundamental diagram feature.

Thunderhead Engineering has also validated Pathfinder’s ability to adapt various fundamental diagrams with extensive experimentation and analysis on selected research. To learn more about this process and other studies on Pathfinder’s results as seen in Figure 2, view the Pathfinder Verification and Validation document. By documenting the engine’s technical implementation and allowing user access to parameters, engineers have more confidence in their own results and analysis.

In addition to the fundamental diagram feature, this version of Pathfinder has a new system of Contour Plots for Advanced Visualization.