Brief Communications

Nature 438, 43-44 (3 November 2005) | doi:10.1038/438043a; Published online 2 November 2005

Theoretical mechanics: Crowd synchrony on the Millennium Bridge

Steven H. Strogatz1, Daniel M. Abrams1, Allan McRobie2, Bruno Eckhardt3,4 & Edward Ott3

Soon after the crowd streamed on to London's Millennium Bridge on the day it opened, the bridge started to sway from side to side: many pedestrians fell spontaneously into step with the bridge's vibrations, inadvertently amplifying them. Here we model this unexpected and now notorious phenomenon — which was not due to the bridge's innovative design as was first thought — by adapting ideas originally developed to describe the collective synchronization of biological oscillators such as neurons and fireflies. Our approach should help engineers to estimate the damping needed to stabilize other exceptionally crowded footbridges against synchronous lateral excitation by pedestrians.

  1. Department of Theoretical and Applied Mechanics, Cornell University, Ithaca, New York 14853-1503, USA
  2. Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, UK
  3. University of Maryland, College Park, Maryland 20742, USA
  4. Fachbereich Physik, Philipps-Universität Marburg, 35032 Marburg, Germany

Correspondence to: Steven H. Strogatz1 Email:


These links to content published by NPG are automatically generated.


Observations on a Wind-Whirl

Nature Letters to Editor (11 Sep 1879)