Crossing Simulation

A two-way road crossing simulation, running fully in the browser via WebAssembly.

Simulation

Controller

Min arrival (s)

Max arrival (s)

Green (s) 13.0s

Yellow (s) 5.0s

All-red (s) 2.0s

Keyboard shortcuts

Space — pause / resume
S — single-step (while paused)
R — restart with the current settings
? — toggle this help

Stats

Total spawned: 0

Elapsed: 0.0 s

Way H (East-West)

Cars on road: 0
Braking: 0
Accelerating: 0
Cruising: 0

Way V (North-South)

Cars on road: 0
Braking: 0
Accelerating: 0
Cruising: 0

Total spawned: 0

Elapsed: 0.0 s

Departed: 0

On the roundabout

Cars: 0
Braking: 0
Accelerating: 0
Cruising: 0

What the settings mean

Controller: How the crossing is managed. Semaphore is a traffic light that alternates right of way between the two roads, braking or stopping cars on red/yellow. DoNothing is a no-op controller — useful as a baseline, or to watch what happens with no traffic control at all.
Min / Max arrival (s): The range, in seconds, for how far apart two cars can arrive on the same road. Each new arrival picks a random gap inside this range — lower values mean busier traffic.
Green / Yellow / All-red (s): Live sliders for the running Semaphore's own timing, once a crossing run with it is started - drag the all-red or yellow slider down to almost nothing and watch a car get caught mid-crossing when the other road's light turns green, then push it back up to see the danger go away. All-red is the brief phase where both roads are red at once, after yellow and before the other road gets its turn.