Use these terms consistently. Several of them look interchangeable in ordinary map code but carry different evidence in Davao Transit.
| Term | Meaning | Where it matters | Avoid confusing it with | Example |
|---|---|---|---|---|
| Route | A public-facing line identity, such as R102. | Catalog, map, search result | A single directed service | R102 can have AM and PM variants |
| Service | A directed operating variant used by the planner. | Graph compilation and search | An undirected LineString | A bus direction is a separate service identity |
| Directional variant | A catalog record that identifies direction, schedule, and stop order. | Bus ingestion | A geometric reversal | R102:AM and R102:PM are not inferred from each other |
| Transfer | A graph edge that permits changing services under an explicit contract. | Planner compiler and selection | Two lines that pass near each other | An official bus stop plus a bounded jeepney endpoint can produce an edge |
| Projection | The operation that maps a coordinate onto a route geometry and returns progress or distance. | Planner access and telemetry | A route match with certainty | A GPS point can project off-route or produce a GPS-jump quality state |
| Passage | A derived event that a vehicle crossed a stop position during a trip run. | ETA and segment statistics | A raw GPS report | A passage needs route progress and continuity evidence |
| Visit | The service-level interpretation of stop arrival and departure evidence. | Transit intelligence | A single stationary observation | Dwell candidates contribute evidence to a stop visit |
| Segment run | A derived movement interval between two ordered stop passages. | ETA and road comparison | A road segment | It can provide a stop-to-stop runtime sample |
| Planner image | The compiled static graph artifact consumed by the browser worker. | Build, cache, and mount | A database or hand-maintained binary | The current public artifact ends in .wayplan |
| Confidence | A statement about the evidence supporting a derived value. | Telemetry, ETA, assistant fallback | Certainty that the value is true | A recent arrival with enough samples can have higher confidence |
| Direct access | Coordinate-distance walking from an endpoint to a service geometry. | Trip selection and rider copy | A pedestrian street route | The current planner uses a geometric estimate |
| Live arrival | A runtime observation attached to a service or stop. | Tracker and enrichment | Static schedule data | The current browser planner sends an empty live-arrival list |
The system invariants define the boundaries behind these terms. The planner engine and telemetry pipeline show how the terms connect in code.