Accordion effect

In physics, the accordion effect occurs when fluctuations in the motion of a travelling body causes disruptions in the flow of elements following it. This can happen in road traffic, foot marching, bicycle racing, and, in general, to processes in a pipeline. These are examples of nonlinear processes. The accordion effect generally decreases the throughput of the system in which it occurs.

The accordion effect in road traffic refers to the typical decelerations and accelerations of a vehicle when the vehicle in front decelerates and accelerates. These fluctuations in speed propagate backwards and typically get bigger and bigger further down the line, decreasing the throughput of road traffic.

The accordion effect is known by various aliases such as the 'slinky effect' or the 'Concertina effect', or the 'string instability'.

See also

Wavelength
Doppler effect

References

SA Nobe, FY Wang - PROC IEEE INT CONF SYST MAN CYBERN, 2001 - ieeexplore.ieee.org

Y. Sugiyama1, M. Fukui, M. Kikuchi, K. Hasebe, A. Nakayama, K. Nishinari, S. Tadaki and S. Yukawa, "Traffic jams without bottlenecks-experimental evidence for the physical mechanism of the formation of a jam", New Journal of Physics '10' (2008), p.033001, doi: 10.1088/1367-2630/10/3/033001, url:http://iopscience.iop.org/1367-2630/10/3/033001/fulltext/

Physics Encyclopedia