How Does Geofencing Work for Fleet Management?

Quick answer: Geofencing involves creating a virtual boundary around a real world location based on GPS coordinates and setting an action that takes place when the boundary is crossed. Once a tracked vehicle or asset enters or exits the zone, the system records the event and can trigger an alert, an email or even an automated workflow.

Key Takeaways

• A geofence is a virtual GPS boundary around a place; geofencing is the practice of using it to trigger actions.
• It operates according to an ‘if this-then-that’ rule: if the boundary is crossed, then the system notifies or automates something.
• Three common shapes are the circular, the polygon and the route-corridor, all appropriate to different jobs.
• Real fleets are using it for alerts on unauthorized use and arrival/ETA automation, theft prevention, and even compliance logs.
  The accuracy is generally less than 10 meters when open; the primary challenges are “alert fatigue” and “zones too tight.

This guide will help you understand the basics of geofencing, how it works, what types of geofences exist, the impactful use cases, and how to implement it without being overwhelmed by false alerts. To learn more about mechanics, read our GPS tracking how GPS tracking works.

What Is Geofencing?

A geofence is a metaphorical perimeter on a map, which is established around a physical location by GPS coordinates. Geofencing involves setting up those boundaries and then taking some type of action when the tracked device enters them.

It’s an idea that’s easy to understand, but it’s quite a change in how location data can be used. Plain GPS tracking provides information about the current location of a vehicle. Geofencing lets you know if the vehicle is at the location it is supposed to be and it doesn’t require anyone to look at a map to determine this. The same underlying technology powering a wide variety of users: a fleet manager that checks crew arrivals, a logistics company that safeguards equipment on a job site, a parent that knows when a child’s car leaves school. Only the rules and alerts are different; the technology remains the same.

How Does Geofencing Work?

Geofencing brings three things together that exist in any tracking system, GPS to find the location, a cellular network to communicate that location to a server and software to compare the location to your boundaries. The loop it goes through is:

1. A GPS device reports its position. These vehicles/ assets send their location (latitude and longitude) every 10 to 60 seconds.
2. You draw a boundary on the map. You outline an area around any location, a depot, a customer site or a restricted area using the map interface of the platform.
3. The software watches for crossings. It constantly checks the coordinates of each device against all active geofences.
4. A crossing triggers a rule. As soon as a vehicle is detected as entering or exiting a zone, the system triggers the action you’ve set up, such as a push notification, SMS, email, dashboard alert, compliance log entry or an automated workflow.

That’s the whole reason! Modern geofencing is executed based on an ‘if this then that’ principle: If a truck leaves the depot after 10pm, then alert the operations team immediately. The difference between being told of a problem as it is occurring and the following morning. This is why “active” geofencing, which can act in real-time, has now become the most popular – accounting for more than 50% of the market by 2026.

What Are the Types of Geofences?

Most platforms will offer three types of geofence shapes and choosing the appropriate shape for the appropriate location is the way to get a clean alerting system versus false alarms.

Geofence Type	Shape	Best For
Circular (radius)	A center point with a set radius	Customer sites, fuel stations, single-address depots
Polygon	A custom multi-point boundary	Job sites, warehouses, irregular yards, territories
Route corridor	A boundary along a planned route	Regulated routes, hazmat, deviation detection

The fastest to create is a circular geofence (one click and a radius) and is useful for simple points of interest. A polygon geofence allows users to define an irregular shape by plotting a series of points, which is useful for a construction site or a site of a large building where the circle would extend past the property and cause false alerts. A route corridor is a planned path with a prescribed width, and indicates any change in the path width, which is critical to regulated or hazmat routes.

Fleet Geofencing Use Cases

This is where “geofencing comes into play. The same technology is used but for very different ends when you set your bar differently and activate different reactions.

• Unauthorized-use alerts. The area surrounding the depot is tightly cordoned off and there is an out-of-hours rule – any vehicle moving when it should not is marked as a tight vehicle. A change like this usually shows up when fleets inform drivers of the limits that are being enforced and that their after-hours driving activities are being tracked.
• Arrival and ETA automation. A geofence is placed around a customer site to automatically record arrival and can alert the customer of their arrival, eliminating the “where’s my delivery?” calls without the need for a dispatcher to lift a finger.
• Theft and asset protection. With trailers, generators or equipment being left overnight, there can be a strict perimeter with a night time rule that causes the moment the asset moves to escalate and sometimes the device goes into recovery mode.
• Compliance and timesheet logs. Geofence entry/exit events generate GPS verified and auditable site visits to provide documentation for insurance and audits and eliminate driver self-reporting.
• Route adherence. A route corridor flags detours, providing drivers with information to stay on approved paths and minimize unauthorized driving.
• Workflow automation. Advanced setups send a boundary crossing to another system as an action, update a TMS on arrival or validate a refrigerated delivery if the temperature and driver checks validate successfully.

Fleets that use geofencing as a safety and compliance tool see tangible results, such as significant decreases in employee unauthorized vehicle use, fewer inbound ETA requests and lower idle time fuel costs.

How Accurate Is Geofencing?

The GPS positioning accuracy is the accuracy that can be achieved, which is largely determined by the GPS device and the time interval between reports. Under open conditions, modern trackers are quite precise within approximately 10 meters, which is sufficient to determine that a vehicle is at a certain address. That number is subject to 3 influencing factors:

• GPS signal strength. Variance can even reach 15–30 meters in dense cities, tunnels and underground parking.
• Update frequency. A crossing is detected automatically in almost real time with a device reporting every 10 seconds, while the device reporting every 60 seconds can lag.
• Geofence size. Small zones around gates or loading bays will generate unnecessary alarms because vehicles will move in and out as they are expected to.

Outdoor accuracy is reduced inside of buildings, however, geofencing does work for vehicles since once it gets a fix, it triggers the boundary on crossing it before it loses signal in the covered garage.

Geofencing Setup Best Practices

The overwhelming majority of geofencing issues is actually setup issues, not technology issues. There are a couple of practices which maintain the trustworthiness of the system:

• Start with your highest-value locations. First restricted areas, depots, fuel stations, then all locations.
• Match the shape to the place. Circles if the address is circular, Polygons if the address is irregular, Corridor if the route is a corridor.
• Add a dwell buffer. By having the vehicle inside or outside for 30-60 seconds before firing, false alerts will not occur if the vehicle is stationary near a boundary.
• Avoid over-tight zones. In GPS-challenged areas, don’t set up a perimeter less than 15 metres.
• Prioritize alerts. The worst thing you can do for a geofencing program is to let too many irrelevant alerts fire and for teams to tune them out and not get the alerts they need. Direct only what’s relevant to those who need it.

Where AIQConnect Fits

The idea and physics of geofencing is the same everywhere, as is the fact that it is a standard feature of any serious tracking application. The difference lies in the degree of flexibility with which zones and rules can be configured and the location of the data that backs the zones.

A self-hosted platform with geofencing, entry/exit alerts and rule-based automation means that the boundaries you draw and the movement data you generate will remain on your own server and not a vendor’s cloud! If you are operating in the vicinity of sensitive routes or valuable assets, it may be the case that you need to have that location intelligence in-house or in-house data. This is not the only factor, self-hosted geofencing may be considered if data ownership is key, for example, in a very small operation, but in other cases, a plug-and-play cloud tool may be preferred.

To go deeper, see how GPS tracking works, the benefits of self-hosted GPS tracking software, or the best GPS fleet tracking systems.

Frequently Asked Questions

What is geofencing in simple terms?

Geofencing is effectively creating a virtual boundary around a real world location by using a set of GPS coordinates which once crossed will be logged in the system and an alert or action can be sent to the system.

How does geofencing work?

It uses GPS to detect a device’s location, a cell network to relay that data to a server, and software to analyze the GPS data and compare it with your boundaries. Action can be triggered when a device crosses a boundary, notifying with an alert, logging, or starting an automated workflow.

What are the types of geofences?

There are three general shapes: circular (center point and radius), polygon (a user defined multi-point shape), and route corridor (a shape that outlines a planned route). Circles are used for one address, polygons for irregular addresses and corridors flag deviations from the route.

How accurate is geofencing?

Typically within roughly 10m in open areas. In dense urban environments, tunnels or covered areas, there is a loss of accuracy to 15-30 meters, depending on how often the tracker can be updated; the higher the more often, the sooner the crossing will be detected.

What is geofencing used for in fleet management?

Some of the common uses are for alerts when users are using the device in a manner they are not authorized to, notifications when the person arrives and when they are expected, theft and asset protection, GPS verification of compliance logs, monitoring of route adherence, and workflow triggering in other systems such as TMS.

What is the difference between active and passive geofencing?

Active geofencing identifies boundary crossings in real time and can intervene during the boundary crossing. Passive geofencing: Records events for later review. Active geofencing has replaced passive geofencing as the preferred method as it allows the managers to take actions in real time.

Why do geofencing alerts sometimes fire falsely?

Typically due to a narrow zone or due to the fact that the vehicle is stationary close to a boundary. Dwell buffer – 30-60 seconds inside or outside before triggering – and not using areas closer than 15 meters in GPS challenged areas decrease false triggers.