Controls

Road length L: 200 cells Cars: 60 (density 0.30) v_max: 5 cells/step Randomization p: 0.30 Sim speed

Slow-to-start rule

Statistics

Cars60

Density ρ0.300

Mean velocity0.00

Flow Q0.000

Jam fraction0%

Step0

NaSch rule (per step, all cars in parallel):
1. Accelerate: v ← min(v+1, v_max)
2. Brake to gap: v ← min(v, gap)
3. Randomize: with prob. p, v ← max(v−1, 0)
4. Move: position ← position + v (mod L)

The random step is what makes "phantom jams" appear from a perfectly uniform start. Watch the diagonal stripes in the space-time plot — those are jam waves drifting backwards while every car drives forward.