Fair comparison: both modes receive an identical pre-generated vehicle roster (same arrival times, speeds, neutral spawn lanes). EU mode reassigns each vehicle to its speed-matched lane on entry; US mode uses the neutral lane as-is.
Road & time
3
3000
33
600
0.50
Shared spawn process
0.35
22.0
7.0
Speeds clamped to [4, limit+5]. Both modes draw from the same distribution.
Physics
1.20
5
2.00
60
100
EU lane assignment: each vehicle's speed is matched to the lane with the closest μ. Used only for EU lane assignment, not for speed sampling.
EU European — final state
US American — final state
Playback — EU (top) vs US (bottom). Normal color = cruising, lighter = overtaking.