A GPS vehicle tracking system works by having a device fitted to the vehicle calculate its position from satellite signals and send this data over a GSM or satellite network to a software platform. The platform shows the location on a map, stores the route history and generates speed, stop and geofence violation alarms. This lets the cargo owner see where the shipment is and when it will arrive.
The three core components of the system
- On-board device: Contains a GNSS receiver (which can use GPS, GLONASS, Galileo and BeiDou satellites together), an accelerometer, a backup battery and data memory. Advanced devices read fuel, engine speed and mileage data from the CAN bus, and driver identity and working time from the tachograph; they can be connected to door and temperature sensors.
- Communication layer: Position packets are transmitted to the server over mobile data (2G/4G). Outside network coverage the device stores records in memory and sends them in bulk once it is back on the network; on ocean or desert routes, devices with satellite modems are used.
- Software platform: Plots incoming data on the map, produces reports, manages alarm rules and user permissions, and transfers data to transport management systems via API.
How is the position calculated, and how accurate is it?
The receiver calculates latitude, longitude, altitude and time by measuring how long signals from at least four satellites take to arrive. According to the US government's GPS.gov website, GPS-enabled smartphones are typically accurate to within a 4.9-metre radius under open sky; tall buildings, bridges and trees reduce this accuracy. For vehicle tracking, an error of a few metres causes no practical problem. The real loss occurs where the signal is cut off entirely, in tunnels, enclosed car parks, ship holds and under port cranes; what can be done in such cases is explained in the entry vehicle tracking in areas without GPS signal.
How often is the position updated?
The update interval is a device setting and a trade-off between data cost and level of detail. In a common setup, the position is sent every 30 seconds to 2 minutes while the vehicle is moving and every 15–60 minutes when it is stationary. Many devices also generate intermediate records on a change of direction, when the ignition is switched on or off, or when an alarm is triggered. This ensures the route history is drawn without gaps at bends and junctions.
Alarm and reporting features
- Geofence alarm: Generates a notification when the vehicle enters or leaves a defined area, such as a factory, port or border crossing zone.
- Route deviation: Issues a warning when the vehicle moves a set distance away from the planned route.
- Speed and long stops: Speeding or unplanned long waits are recorded.
- Sensor alarms: Door opening, a temperature deviation in a reefer trailer or removal of the device is reported.
- Reports: Daily mileage, stop lists, waiting times, driver behaviour and estimated time of arrival (ETA) are produced.
Visibility for the cargo owner
Tracking data can be made available not only to the fleet owner but also to the cargo owner. This is usually done via a time-limited sharing link, regular location reports by e-mail or a customer portal. The information a portal can offer is described in the entry logistics customer tracking portal. When location data is connected to a transport management system (TMS), shipment status, delay alerts and the delivery record come together on a single screen.
Who is responsible, and the personal data dimension
Installation and maintenance of the device are usually the responsibility of the carrier that owns the vehicle, while sharing the data with the customer is the responsibility of the carrier or the forwarder. When location data is linked to a driver, it counts as personal data under Personal Data Protection Law No. 6698 (Kişisel Verilerin Korunması Kanunu, KVKK). The driver must be informed, the data must be processed in a way that is limited to the purpose and proportionate, and a retention period must be set; details are in the entry vehicle tracking data and KVKK.
Common mistakes
- Fitting the device only to the tractor and leaving the trailer untracked; on trips where trailers are swapped, the cargo cannot be followed.
- Setting alarm thresholds too low; constant false alarms cause real incidents to be missed.
- Keeping route history for too short a time; no evidence remains in a damage or delay dispute.
How does Voltim Global support you?
With its daily vehicle tracking and reporting service, Voltim Global monitors the vehicle's location throughout the shipment and sends the cargo owner regular location updates.