Fundamental diagram of traffic flow
The fundamental diagram of traffic flow is a diagram that shows the relationship between traffic volume (vehicles per hour, also known as traffic flow) and traffic density (vehicles per kilometer). The fundamental diagram is based on a macroscopic traffic flow model that describes the relationship between traffic density, traffic speed and traffic volume. With the fundamental diagram, statements can be made about the permeability of a street section. In addition, simulations can be made of how the traffic flow behaves in the case of flow control , speed limits or other measures.
Essential statements
- There is a relationship between traffic density and vehicle speed: the more vehicles drive on a section of road, the lower the driving speed.
- In order to avoid traffic jams and to keep the flow of traffic stable, a maximum of as many vehicles may enter a road section as can exit the section during the same period.
- With a critical vehicle density and a corresponding vehicle speed, the state of the traffic flow changes from stable to unstable.
The fundamental diagram is of particular importance in the design of traffic facilities as well as traffic management systems.
See also
- Traffic physics
- Traffic engineering
- Three-phase traffic theory
- Nagel-Schreckenberg model
- PELOPS (traffic flow simulation program)
- Traffic performance
Web links
Commons : Fundamental Diagrams - collection of images, videos and audio files
