Geofencing in logistics defines virtual geographic perimeters tied to sites — plants, DCs, customers, yards — that generate automatic events when a GPS (satellite location) asset enters, dwells, or exits. It is the foundation for appointments, OTIF on-time, detention, and deviation alerts.
The carrier swears arrival at 10:00. The DC says 10:42. The GPS PDF shows a pin 1.2 km away. Without gate/dock geofences, both can be “right.” It lives in the fleet management cluster with GPS and telematics.
- enter / exit / dwell
- Event
- typical appointment tolerance
- ±30 min
- gate ≠ dock
- 2 fences
- coverage target (calibrate)
- ≥95%
What geofencing is (usable answer)
It is not “a pretty circle on the vendor map.” It is an operating contract: site name, shape (circle or polygon), radius or vertices, and the business event it fires (T−45 alert, gate arrival, at dock, departure).
Without wiring to the trip ID in the transportation management system (TMS), the geofence stays in the GPS portal and your OTIF board keeps fighting illegible tickets.
Geofence layers: approach, gate, dock
Design distinct layers. One huge fence inflates “on time” and starts detention fights.
Approach (5–8 km)
Typical radius / shape: Wide circle
Business event: T−45 / late risk
OTIF use: Preventive alert
Gate
Typical radius / shape: 80–200 m or polygon
Business event: Arrived site
OTIF use: On time if SLA says so
Dock
Typical radius / shape: 30–80 m or polygon
Business event: At dock / unload
OTIF use: Strict on time + detention
Yard
Typical radius / shape: Irregular polygon
Business event: Waiting
OTIF use: Detention exclusions
Customer store
Typical radius / shape: 50–120 m
Business event: Delivery window
OTIF use: Last mile
Practical design at Mexico sites
Large DCs (Perinorte, FIDENA, Bajío parks): use polygons, not circles. Circles swallow avenues and mark false arrived while 25 minutes of queue remain.
Appointment tolerance: combine geofence timestamp ± SLA minutes (e.g. ±30). Without both, the number is not defensible to the retailer. Cross with delivery window and detention.
GPS vendor criteria (API vs mirror account, coverage) live in the 2026 comparison — no invented single winner.
Why it matters by role
| Role | What they gain | If the fence is theater |
|---|---|---|
| Tower / traffic | Actionable T−2h alert | Retrospective dashboard only |
| DC / customer | Defensible appointment clock | Minute disputes |
| Carrier | Detention defense | Ticket vs pin 1 km away |
| Accounts payable | Timestamp in trip file | Pays accessorials blind |
Implement operable geofencing in 5 steps
Prioritize sites for 80% of volume. Calibrate two weeks before celebrating the KPI.
Inventory sites
Top 80% volume
Gate and dock
Two events
Wire to trip
TMS, not portal
Pilot calibrate
False +/-
Alerts + detention
Owner acts
Myths and expensive mistakes
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Detalle del paso · 01
“Carrier GPS is enough”
OCL and the trip file
OCL Cargo is an autonomous TMS: it consumes geofence events for early alerts, detention, and on-time evidence without depending on chat. It does not draw your polygons or replace your FMS. When applicable, it can stamp invoices and Carta Porte; it audits the trip file. Pattern 5–7% when auditing 100% of freight — calibrate to your operation.
Key takeaways6 points
- Geofencing = a virtual GPS perimeter that fires enter/exit events: plant, dock, customer.
- Without a dock geofence, “on time” is neighborhood arrival — useless for a ±30 min appointment.
- Use layers: approach (alert), gate (arrival), dock (detention / strict OTIF).
- In Mexico: polygons at large DCs; not one huge “Mexico City” fence.
- Geofence + appointment in the TMS = auditable clock; WhatsApp is not.
- OCL wires events into the trip file. It does not draw your fences. It can stamp invoices and Carta Porte when applicable.
Do you measure on time with a geofence — or with opinions?
Related reading
Frequently asked questions
Virtual perimeters tied to sites (plant, DC, customer, yard) that fire automatic events when a GPS asset enters, dwells, or exits. Used for appointments, on-time, detention, and security.
It gives an objective arrival timestamp at site or dock for the on-time leg of OTIF, aligned to the appointment window in the service-level agreement (SLA).
Gate is often 80–200 m or a polygon; dock is smaller (30–80 m). Large Mexico DCs need polygons, not wide circles.
Partially. Set a minimum coverage target, report % of trips with a valid event, and keep a document fallback. Without that the KPI lies.
No. Geofence proves arrival; POD / ePOD proves delivery and quantity. They complement each other.
It consumes geofence events for early alerts, detention, and on-time evidence without depending on chat. It can stamp invoices and Carta Porte when applicable.