A two-phase junction serves two conflicting approaches. Change green allocation, demand and saturation discharge. Signals change through green, amber and all-red while the approach queues grow or drain.
• 3D scene parts: Conflicting approaches; signal heads; a vehicle queue; b vehicle queue; phase controller. • Controls: Cycle length (40–140 s); A share of available green (20–80 %); A arrival demand (100–1500 veh/h); B arrival demand (100–1500 veh/h); Saturation flow per approach (1200–2200 veh/h). • Live readouts: A capacity (veh/h); B capacity (veh/h); A queue (veh); B queue (veh); Total departures (veh); Vehicle balance error (veh). • Guided experiments: Overloaded A; Balance equal arrivals; Give A more green. • Four tabs (visual laboratory, curves and measurements, experiments, learn and assess), a model-verification run, a timestamped event log and a trial report.
gA=(C−8)split; gB=C−8−gA cA=s gA/C; cB=s gB/C dQ/dt=arrivals−departures; Q≥0 Amber 3 s + all-red 1 s after each green
Two-approach deterministic fluid queues. Green is treated as effective discharge time; no startup loss beyond the explicit transitions, turning traffic, spillback or pedestrian phases. Vehicle markers illustrate fluid flow rather than individual car-following. Try the preset experiments, then compare the live readouts with the equations.
No. The phase state machine includes mutually exclusive greens.
Yes. Their shares sum to the available green.
Two-approach deterministic fluid queues. Green is treated as effective discharge time; no startup loss beyond the explicit transitions, turning traffic, spillback or pedestrian phases. Vehicle markers illustrate fluid flow rather than individual car-following.