Nikolaus Dietz , Department of Physics & Astronomy @ GSU



Rush-Hour Traffic: The transition from laminar to turbulent traffic flow



During your morning and/or evening rush-hour commute, were you ever left puzzled by the phenomenon that as the traffic get really dense, the traffic flow goes over in a "hold - drive - hold - drive" mode, even though there is no accident or any other reasons that block the road? And, what is even more puzzling, after you got through some major intersections which took some traffic off your road, the traffic is back in a smooth flow again, without that you realized any change in the traffic behavior!

If you think about it, the rush-hour phenomenon depict above has many analogies in nature, e.g. (exempli gratia) the flow of water or wind in confined canals or across/around obstructions. Airplane and car industries spent billions of dollar each year to optimize the shape of cars and planes in order to minimize the flow resistance of objects and with it to increase the mileages you can drive/fly per gallon gasoline. The savings would be even greater if we would put a similar effort in modeling and understanding of traffic flow and how to optimize the traffic flow such that we maintain smooth (laminar) flow and avoid "hold - drive - hold - drive" (turbulent) flow!


As a physicist you should be able to:

As an optic student you should know why photons never get in a traffic jam!




Research activities in traffic flow modelling:
              Still Flowing: Approaches to Traffic Flow and Traffic Jam Modeling     (pdf-file: 2.2MB)
              Modelling traffic flow fluctuations
              Amazon.com: Traffic flow: Books


Return to: Teaching Homepage | Physics | Georgia State University


January 15, 2004