D.C. Several researchers from the Institute of Transportation Studies at the University of California, Davis, will be giving presentations at this meeting, which annually attracts more than 8,000 transportation professionals from around the world. Among the ITS-Davis presentations will be the following. As every commuter knows, freeway traffic can slow down and stop, sometimes for no obvious reason.
Scientists compare the flow of traffic to the flow of liquid through a pipe.
Smooth, or laminar, flow moves high volumes quickly. When the flow becomes turbulent, or chaotic, the flow rate drops. Mathematical models of freeway traffic can reproduce smooth flow, but it has been difficult to make the same models create chaotic traffic jams, according to ITS-Davis researcher Michael Zhang. Zhang and his colleagues have developed a new mathematical model that includes variables for factors such as driver alertness, and driver habits such as speed and tailgating. By capturing these human variables, they can reproduce the transition from order to chaos on the freeways.