The word geofence is also written geo-fence. In logistics, geofences go around the places freight starts, stops and ends: warehouses, yards, ports, customer docks and delivery addresses. The fence itself does nothing; its value is the action it sets off without anyone having to watch a map, such as logging when a truck reaches a dock, telling a customer a delivery is close, or flagging a trailer that leaves a yard when it should not.
How Does a Geofence Work?
The simplest geofence is a point and a radius, which makes a circle around the location. Some fleet and delivery platforms also accept a polygon traced around a site's actual boundary, which fits a long, narrow yard better than a circle.
A dwell event fires only after a device stays inside for a set time, and Google recommends it to cut down the alerts set off by a device that only passes through.
Static and Dynamic Geofences
A static geofence stays in one place, around a warehouse, a distribution center, a customer's site or a restricted area. Many logistics uses are static: the place matters, and the fence marks it.
A dynamic geofence moves or changes. It can follow a vehicle, so that anything leaving a set distance from it raises an alert, or it can be created for one job, such as a fence around today's delivery addresses that disappears once the route is done.
How Geofencing Is Used in Logistics
- Arrival and departure times. A fence around a shipper's or receiver's facility records when a truck arrives and leaves without the driver calling in. Those times feed track and trace updates and show how long a truck waited, which matters when a carrier bills a detention fee.
- Dock and yard planning. A fence a few miles out from a warehouse can alert the dock that a truck is close, so a door and a crew are ready. Inside the gate, a yard management system (YMS) can use fences to log which trailers have entered or left the yard.
- Customer delivery notices. In last-mile delivery, a fence around the drop-off point can send an "arriving soon" message when the driver gets close.
- Proof of location. A delivery app can check that the driver's device is inside a fence around the address when the delivery is marked complete, which supports proof of delivery (POD).
- Security. An alert when a loaded trailer or high-value asset leaves a yard after hours, or when a vehicle enters an area it should not, gives the operator a chance to act early.
- Time and safety on site. Fences around a job site or a hazardous area can record when workers arrive and leave, or warn a driver approaching a restricted zone.
Many of these run inside fleet telematics platforms, a transportation management system or a delivery app, rather than as a separate tool.
Accuracy and Timing Limits
A geofence is only as good as the location fed into it. On Android, location is usually accurate to 20 to 50 meters with Wi-Fi available, and Google recommends a fence of at least 100 to 150 meters. Without Wi-Fi, as on a rural road, accuracy can degrade to several hundred meters or several kilometers, and Google says to use a larger radius. Alerts lag too: usually within 2 minutes, about 2 to 3 on average for a background app, and up to 6 when the device has been still. A telematics unit that reports on a schedule cannot trigger a server-side fence until its next report, though some units hold the fence on board. So size the fence to the job: wide for an "arriving soon" message, and tight, with a dwell time, for logging a truck at the dock.
Privacy and Legal Limits
Geofencing works only when a device shares its location. Tracking drivers and warehouse staff raises employment and privacy questions, so tell people what is tracked, when and why, and check the rules where you operate.