A national average on-time rate hides the northern corridor’s overnight staging reality. Coordinators in Don Mueang who mix southern coastal lanes with Chiang Mai runs need corridor-level boards, or the scorecard rewards the wrong behaviour.
Split measures by corridor only when a named coordinator owns each strip. Shared ownership produces polite boards that nobody updates. If staffing cannot support two owners, keep one board but colour-code corridor rows rather than blending totals.
Northbound punctuality should reference the agreed staging window, not a generic city ETA. Many northern runs plan a Nakhon Sawan pause; treating that pause as delay invents false reds and erodes trust in the board.
Bring carrier mix into the corridor strip only when the desk can act on it — for example, when two carriers share the same lane and the coordinator chooses nightly allocation. Decorative carrier charts belong in monthly management packs, not on the wall.
Test the split during a normal week before peak. If updating two corridor strips doubles the handover time, simplify the secondary corridor to three cells until the habit settles.