- Do groups stay together?
- Do groups keep their velocity when walking along a free path
- Do group members walk abreast?
- Are they capable of splitting and reuniting while avoiding obstacles?
- Do larger groups split in subgroups?
- Do they still stay together as a whole group?
- Do they reunite?
Visual Observation of Small Groups
- Group sizes: 1 to 5
- Wide corridor
- Source on one end and target at the other end
- Additionally a column is placed in the path of the pedestrians
- Each group stays together. No group member is lost.
- Group members walk abreast as long as the path is free.
- Faster groups pass slower groups.
Density-Flow Dependency for Groups
- Group sizes: 1 to 5, one per experiment
- Corridor of length: 200 meter
- Narrows from 20 to 4 meter
- Source at wide end and target at narrow end
- Compare results to Oberhagemanns's diagrams
- Measure density when a quasi-stationary flow establishes for at least 100s during a simulated time of 1000s to 4000s.
- The velocities match in the sense that they are of the same order of magnitude.
- For each group size, that is for each diagram, the velocity decreases with density in a way that roughly matches the measurements (order of magnitude).
- The bigger the group size the slower the progress. The diagrams form a family of curves one lying above the other.
- The difference between the diagrams disappears with very dense crowds.
A Quantitative Test for a Classroom Egress
- Group sizes: 1 to 4, one per experiment
- see ...
- Compare egress time to empirical experiment (see..)
- The simulated egress times match the measurements in their order of magnitude.
- The egress time increases with the group size.
- A more refined model should allow calibration to a quantitative fit within a certain margin.
Visual Observation of Large Groups
- Walking Across an Open Field
- The members of each large group stay together. No group member is lost.
- Each large group divides into small subgroups for which the rules of the small communication groups apply.
- Faster groups pass slower groups. They may split up temporarily, but reunite when the path is free.
- When a large group passes another group
- Visual tests for small groups also apply
Egress of a Large Room
- Extrapolation of a Laboratory Experiment
- 180 soldiers gathered in a room connected to a corridor
- corridor width: 1,4 meter
- corridor length: 4 meter