Nagel-Schreckenberg Traffic Model

A theoretical model of highway traffic demonstrating the spontaneous emergence of "phantom traffic jams."
This visualization shows 60 independent circular lanes (wrapped horizontally). The top lane has the lowest car density, and the bottom lane has the highest.
Each car follows 4 simple rules: (1) Accelerate if below speed limit, (2) Brake to avoid hitting the car ahead, (3) Randomly brake (dawdle) with some probability, and (4) Move forward. Watch how high density (bottom rows) triggers backward-propagating traffic waves.