From the standpoint of hydrodynamics, the transport stream - it is a liquid Bashny.Net

The rapid development of transportation, increasing the number of vehicles, the expansion of the road network leading to the need to optimize traffic flows. Transport problems began to engage in the early 20th century, there were already the first works on the calculation of the main roads of congestion and bandwidth. During the last century there were many scientific concepts related to transportation problems, modeling of traffic has grown into an independent branch of mathematics.

One of the concepts is to consider traffic flow in terms of hydrodynamics, the rapid development of which occurred in the middle of the last century. Liquids and gases comprised of myriad particles are considered separately is not possible. However, hydrodynamic laws allow to describe the behavior of liquids and gases in general. Modern traffic flows are made up of millions of cars, and consideration of each vehicle requires a lot of computing power. For example, the forecast of the transport situation in the big city for an hour by the number of computational operations compare with the weather forecast for the week.

To simplify the problem, it suffices to imagine that the transport stream - is a two-dimensional incompressible fluid, and the ramp - a section of the pipe or, for example, a blood vessel. Indeed, the bird's-eye view road network resembles the circulatory system, and major highway without reason called the transport arteries of the big city.

via factroom.ru