Microscopic traffic flow models are a class of scientific models of vehicular traffic dynamics.

In contrast, to macroscopic models, microscopic traffic flow models simulate single vehicle-driver units, so the dynamic variables of the models represent microscopic properties like the position and velocity of single vehicles.

Car-following models

Also known as time-continuous models, all car-following models have in common that they are defined by ordinary differential equations of the leading vehicle. The equation of motion of each vehicle is characterized by an acceleration function that depends on those input stimuli:

vehicles in front. The equation of motion in this more generalized form reads:

Examples of car-following models

• Optimal velocity model (OVM)

• Velocity difference model (VDIFF)

• Wiedemann model (1974)

• Gipps' model (Gipps, 1981)

• Intelligent driver model (IDM, 1999)

• DNN based anticipatory driving model (DDS, 2021)

• Rakha-Pasumarthy-Adjerid model (RPA model)

• Fadhloun-Rakha model (FR model)

Cellular automaton models

Cellular automaton and the time is discretized. Each road section can either be occupied by a vehicle or empty and the dynamics are given by updated rules of the form:

).

.

Although cellular automaton models lack the accuracy of the time-continuous car-following models, they still have the ability to reproduce a wide range of traffic phenomena. Due to the simplicity of the models, they are numerically very efficient and can be used to simulate large road networks in real-time or even faster.

Examples of cellular automaton models

• Rule 184

• Biham–Middleton–Levine traffic model

• Nagel–Schreckenberg model (NaSch, 1992)

See also

• Microsimulation

References