Geofence meaning

By the Autowhat AI team · Updated 2 Nov 2026

How does geofencing work?

A geofence is usually a circle (a centre point and a radius) or a polygon traced around a site. A GPS tracker or phone reports its position every few minutes. Each time a position arrives, software checks whether it falls inside or outside the boundary. A change from outside to inside is an entry; the reverse is an exit. Nothing is installed at the site itself; the fence exists only in software.

How is a geofence used in truck tracking?

• Arrival and departure. Entry into the consignee's fence marks arrival; exit from the plant fence marks dispatch.
• Detention evidence. Time between entry and exit at a customer site is the waiting time a transporter can claim.
• Unscheduled halts. A stop outside any known fence for longer than a set time is flagged.
• Route checks. A corridor fence along the planned highway shows route deviation.

Worked example: proving detention with a geofence

Illustrative numbers only. A truck's tracker pings every five minutes. The consignee site has a 300 m geofence.

If the contract allows 12 hours free time, about 9 hours are claimable. Because pings are five minutes apart, each timestamp can be off by up to five minutes, which is why detention clauses usually round to the hour.

How big should a geofence be?

Too small, and GPS drift or a truck parked on the road outside the gate never registers as arrived. Too large, and a truck at the dhaba down the road counts as arrived. A large plant with a parking yard needs a wider fence, or a polygon, than a city warehouse. Draw it on a satellite map, include the parking area, and test it with a few real trips before trusting the alerts.

Common mistakes and confusions

• Geofence vs geotag. A geotag is a location stamped on a photo or record. A geofence is a boundary that events are measured against.
• Using the registered address pin. The pin for a company's address is often the office, not the loading gate.
• Slow pings. A device that reports every 30 minutes can pass through a small fence without ever being seen inside it.

Hired trucks rarely carry GPS the shipper can see. A trip-based truck tracker such as Portable GPS Tracker goes into the cab at the gate, sends 4G pings every few minutes, flags long halts and silent devices to the desk, and closes the trip at the destination. For staff attendance, the same idea is covered in geofence attendance; for tracking options on market vehicles, see how to track a hired truck's live location.

Where this shows up in our work. Portable GPS Tracker: A 4G device in any truck — owned or hired — tracked live with temperature, a customer link and every device collected. Book a 30-minute working session with an engineer.

General guidance, current as of the date above. Figures in examples are illustrative. Rules change: confirm with your adviser or the official portal before acting. More terms in the glossary.