Continuum behavior in cycling pelotons

Large-scale collective behavior, known to be exhibited by a range of species including birds, insects, fish and even humans, results in complex spatiotemporal patterns.  These patterns are prominent in pelotons of cyclists in which densely packed bicycle racers move collectively while trying to preserve energy.  The widespread assumption has been that the details of rider arrangement follows primarily from an optimal aerodynamic drafting configuration.  However, we have found that the local group structure tends to follow from something more intrinsic to the riders’ sensory systems.  The resulting interaction principles cause information to propagate through the group in a manner that can be modeled using continuum mechanics.  In this talk, we relate this continuum behavior to the fundamental mechanisms driving interaction and comment on the role of aerodynamics in setting the structure of cycling pelotons.