| Phase | Movement | Split % | Green (s) | Distribution |
|---|
Both rings run simultaneously. Phases on the same side of the barrier can run at the same time — Φ1 with Φ5, Φ2 with Φ6, etc. Both rings must cross the barrier together before EW phases begin.
This is why you can have NB left turns (Φ1) running at the same time as SB left turns (Φ5) — they're concurrent phases in different rings, same side of the barrier.
Current sequence: Φ1+Φ5 → Φ2+Φ6 ⟂ Φ3+Φ7 → Φ4+Φ8
These are the real SNMP OIDs a traffic management center would query on a physical controller. Values update live with the simulation.
NTCIP stands for National Transportation Communications for ITS Protocol — a family of standards that lets traffic management systems from different manufacturers talk to each other over a common language.
Think of it like TCP/IP for traffic signals. A traffic management center (TMC) can connect to any NTCIP-compliant controller — Siemens, Econolite, Intelight, PEEK — and issue the same commands regardless of brand.
1.3.6.1.4.1.1206.4.2.1.1.4.0.The most common traffic controller model in the US is the NEMA dual-ring, 8-phase controller. It has two concurrent "rings," each processing up to 4 phases, with a barrier that forces both rings to sync before crossing.
Ring 1 handles: Φ1 (NB Left) → Φ2 (NB/SB Through) | Φ3 (EB Left) → Φ4 (EB/WB Through)
Ring 2 handles: Φ5 (SB Left) → Φ6 (NB/SB Through) | Φ7 (WB Left) → Φ8 (EB/WB Through)
A timing plan defines how long each phase gets during a cycle. The cycle length is the total time for all phases to complete once. Splits are how that time is divided between phases — usually expressed as a percentage or seconds.
Try adjusting cycle length and splits in the Timing Plan tab. The intersection updates in real time.
Every piece of data on an NTCIP controller has an OID. The NTCIP Objects tab shows live values from this simulation using real OIDs from the NTCIP 1202 standard (Traffic Signal Controller).
OID breakdown: 1.3.6.1.4.1.1206.4.2.1.2.2.1.6.2
→ 1206 = NTCIP enterprise ID · 1 = TSC MIB · 6 = phaseMaxGreen1 · 2 = phase number
cycleLength = 1200 means a 120-second cycle.NTCIP 1202 — Traffic Signal Controller (TSC) — what this simulator implements
NTCIP 1203 — Dynamic Message Signs (DMS)
NTCIP 1204 — Environmental Sensor Stations
NTCIP 1205 — Closed Circuit Television (CCTV)
NTCIP 2306 — XML Message Encoding for NTCIP (application layer)