  Pedestrian dynamics models the walking movement of individuals in a crowd. It
has recently been used in the analysis of procedures to reduce the risk of
disease spread in airplanes, relying on the SPED model. This is a social force
model inspired by molecular dynamics; pedestrians are treated as point
particles, and their trajectories are determined in a simulation. A parameter
sweep is performed to address uncertainties in human behavior, which requires a
large number of simulations.
  The SPED model's slow speed is a bottleneck to performing a large parameter
sweep. This is a severe impediment to delivering real-time results, which are
often required in the course of decision meetings, especially during
emergencies. We propose a new model, called CALM, to remove this limitation. It
is designed to simulate a crowd's movement in constrained linear passageways,
such as inside an aircraft. We show that CALM yields realistic results while
improving performance by two orders of magnitude over the SPED model.
