OTHER TRAFFIC RESEARCH: Mathematicians at MIT were able to explain how traffic jams that seem to have no cause, or phantom traffic jams, get their start. Because the volume of cars on a highway can be heavy at times, the slightest disturbance in the flow can cause a back-up. This includes actions such as a driver tapping a brake too often, getting too close to another car or hitting the brake too hard. The researchers used equations similar to those used in fluid dynamics to design a model based on traffic volume and density to explain this phenomenon. The model explores under what conditions these jams form, intending to help road designers minimize their chances of occurring.
ABOUT FLUID DYNAMICS: The study of the physics of fluids -- matter in liquid, plastic, gaseous, and plasma states -- is called fluid dynamics. Understanding the behavior of matter under different temperature and pressure conditions is important to applications such as the aerodynamics of aircraft and automobiles, the flow of petroleum through pipelines, weather prediction, and even traffic engineering. Other concepts important to solving problems in this discipline include the velocity and density of a fluid.
The American Society of Civil Engineers contributed to the information contained in the TV portion of this report.