Every telematics platform sells geofencing, and almost every fleet that switches it on ends up ignoring it within a few months. The feature works. The problem is that a geofence is a question you ask the system over and over, all day, and most fleets ask badly formed questions.
A geofence is a boundary drawn on the map. When a vehicle crosses it — or stays inside it, or fails to arrive — the platform records an event. Everything useful about geofencing comes from being precise about which of those events you care about, and who needs to hear about it.
Start from the decision, not the map
Before drawing anything, write down the decision the alert is meant to support. If nobody will act differently when the alert fires, it should not be an alert — at most, it is a line in a report.
Common, well-formed uses:
- Arrival and departure at customer sites, feeding real service times back into planning and customer ETA notifications.
- Depot entry and exit, to time-stamp the start and end of the working day automatically.
- Unauthorised areas out of hours, for security on vehicles that should be parked.
- Restricted zones such as city low emission areas or sites with weight limits, where entering has a cost.
- Dwell at places that should be brief, like a fuel station or a lay-by, as a prompt to check rather than as proof of anything.
Poorly formed uses tend to be the ones that turn a location feed into a surveillance tool: fences around a driver's home, around cafés, around every street in the territory "just in case".
Count an arrival only when the vehicle has been inside the zone, and moving slowly or stopped, for a minimum time — a minute or two is common for customer sites.
Shapes and sizes
The geometry decides the quality of the data.
| Zone type | Good shape | Common mistake |
|---|---|---|
| Customer site | Polygon around the yard or bay | A 500 m circle that includes the road outside |
| Depot | Polygon including parking and gates | A circle that misses the overflow car park |
| Urban restricted zone | The legal boundary, imported | A hand-drawn approximation |
| Security zone out of hours | Tight polygon around the parking area | Large zone that catches neighbouring roads |
A circle is quick to draw and usually wrong. Too small, and GPS drift at a covered loading bay produces a flurry of false exits and re-entries. Too large, and a vehicle that simply drives past the customer registers a visit.
GPS accuracy is also worse exactly where fleets need precision: urban canyons, underground loading, covered yards. If your GPS tracking reports position every two minutes, a short stop can fall entirely between two points and never register. Check the reporting interval before trusting short visits.
Alerts: fewer, routed, and with a next step
The fastest way to make geofencing useless is to send every event to everyone by email. Instead:
- Classify each event as act now, review today, or report only. Most events are report-only.
- Route act-now alerts to one named role — the dispatcher on shift, not a distribution list.
- Attach the next step. An out-of-hours movement alert should say who to call, not just where the van is.
- Review the volume monthly. If a rule fires more than a handful of times a day and nobody acts, change the rule or delete it.
The platform's dashboards should then summarise the report-only events: time on site by customer, time at depot, late arrivals. That is where geofencing earns its keep over time, and it connects directly to dashboards and reporting that operations already read.
Privacy: where the line sits
Geofencing is location monitoring of workers, and in Europe that falls under data protection law. The legal detail belongs to your adviser, but the practical principles in guidance such as the UK ICO's material on monitoring workers are consistent:
- Have a clear, documented purpose for each type of zone, and do not reuse the data for something else without reassessing.
- Tell drivers what is monitored and why before it starts, in plain language.
- Respect private time. If vehicles may be used privately, there must be a way to stop tracking during that time, and zones around personal locations are very hard to justify.
- Keep it proportionate. A fence around a customer's yard is easy to justify; a fence around a lunch spot usually is not.
- Set retention periods and delete event data when they end.
Our article on telematics, driver privacy and GDPR covers the wider framework, including when a data protection impact assessment is expected.
Getting started in a month
- Week 1 — List the decisions geofencing should support. Import depots and legal zone boundaries.
- Week 2 — Draw polygons for the top customers by visit count. Set dwell thresholds.
- Week 3 — Run in report-only mode. Compare arrivals with proof-of-delivery timestamps to find badly drawn zones.
- Week 4 — Switch on a small number of act-now alerts with named owners. Brief drivers on what is monitored.
After that, add customer zones gradually, prioritising the sites where service time matters most to the plan.
Frequently asked questions
How many geofences can a fleet realistically manage?
Most platforms handle thousands technically. The practical limit is maintenance: customer sites move, depots expand, legal zones change. Keep zones tied to records in your customer or site master data so they are updated when the address is.
Can geofence data replace proof of delivery?
No. It shows the vehicle was near a place, not that goods were handed over or to whom. It is a useful cross-check against electronic proof of delivery, not a substitute for it.
Should drivers be able to see the geofences?
Showing drivers the zones that affect them — depots, restricted areas, customer sites — tends to improve acceptance and reduces disputes. Transparency is also consistent with the information duties employers have under data protection law.
Why does a vehicle show as leaving and re-entering a site repeatedly?
Usually GPS drift at a zone edge, often under cover. Enlarge the polygon slightly around the bay, add a dwell or exit delay, and check the device's reporting interval.
