Automatic vehicle locationAutomatic vehicle location (AVL) is a method for automatically determining and transmitting the geographic location of a vehicle. This data can be used to create a vehicle tracking system, which is a component of fleet telematics and various location-based services in the Internet of Things (IoT) ecosystem.[1] The most common method for determining location is through the use of a GNSS receiver (such as GPS), which collects positioning data from satellites.[2] This data is then transmitted via a wireless network, typically a cellular network or satellite communication system, to a central server. The server processes this information and makes it available for several applications, from dispatching emergency vehicles to providing real-time arrival information for public transport.[3] AVL is often integrated with other vehicle systems to collect a wider range of data as part of telematics.[4] How AVL worksAn Automatic vehicle location system typically functions in three stages: position determination, data transmission, and data integration. Positioning (determining location)First, a device in the vehicle, typically a GPS tracking unit, determines its geographic coordinates. Most systems use a GNSS (Global Navigation Satellite System) receiver. The receivers calculate their position by processing signals from satellite constellations, such as the United States' GPS, Russia's GLONASS, or Europe's Galileo.[5] In urban environments where satellite signals may be obstructed by buildings, this positioning data can be supplemented with other methods like cellular triangulation or Wi-Fi positioning to maintain a location fix. Data transmission (communicating location)Second, the AVL device, often a telematic control unit, transmits this telemetry data to a central server. The two primary methods of transmission are:
Data integration (using the location)Third, a backend server receives and processes the vehicle location data. This server stores the information and makes it available to software applications through an API (Application Programming Interface). The data is analyzed to support management decisions.[7] This allows a fleet management platform to display a vehicle's position on a map or a public transport application to provide passengers with real-time arrival predictions.[8] ApplicationsAutomatic vehicle location has several applications across commercial, public, and consumer sectors. Fleet managementA common application of AVL is in commercial fleet management, which uses fleet digitalization to monitor and manage vehicles. AVL enables a fleet telematics system to function. It is used to:
Anti-theft and stolen vehicle recovery (SVR)AVL is used to prevent vehicle theft and recover stolen assets. Stolen vehicle recovery (SVR) systems use a concealed AVL device that can be activated after a theft is reported. This tracking system then transmits its real-time location to a monitoring center, which coordinates with law enforcement to recover the vehicle.[10] Some systems include features such as:
Public transit AVL technology is used in public transport operations. Transit authorities use it to feed real-time location data from buses and trains into an intelligent transportation system. This enables:
Emergency servicesEmergency services use AVL to improve response times. A computer-aided dispatch (CAD) system uses the real-time location of all emergency vehicles to identify and dispatch the closest unit to an incident, ensuring help arrives as quickly as possible. Taxi and ride-hailingTaxi dispatch and ride-hailing platforms such as Uber and Bolt use AVL technology. The system's ability to track vehicle locations in real-time allows these platforms to efficiently match passengers with the nearest available driver, provide accurate estimated times of arrival (ETAs), and calculate fares based on the precise distance traveled.[12] CarsharingCarsharing services rely on AVL to manage their fleets of publicly distributed vehicles. The technology allows users to locate and reserve the nearest available car through a mobile app. The AVL system also enables keyless entry, tracks usage time and mileage for automated billing, and provides the vehicle's location for recovery and maintenance.[13] Consumer and OEM services
Construction and heavy equipmentIn the construction sector, AVL is used for asset tracking to track and trace high-value assets like heavy equipment and vehicles. This helps to prevent theft, monitor asset utilization to ensure machinery is being used efficiently, and improve overall project management.[14] Agriculture and smart farmingIn modern precision agriculture, AVL is essential for managing and automating farm operations. The technology is installed on machinery like tractors and harvesters to provide location data. This enables automated steering systems that improve field efficiency, allows for the exact mapping of crop yields, and helps manage the fleet of equipment during planting and harvesting.[15] This data forms the basis of a managing information system for precision farming, which helps optimize resource use and improve crop management.[16] History of developmentAutomatic vehicle location technologies developed from early radio-based systems to the satellite-based standard used today. Early radio-based systemsBefore satellite navigation, early forms of AVL relied on terrestrial radio systems. One of the first methods was radio direction finding (RDF), which used triangulation to estimate the location of a vehicle's transmitter based on its signal's bearing from two or more fixed radio sites. While functional, its accuracy was limited. In the 1970s, some systems were developed that adapted the marine-based LORAN-C navigation system for vehicle use. A LORAN receiver in the vehicle would calculate its latitude and longitude and transmit the data via a two-way radio to a central dispatch, where the location would be plotted on a map. These systems were functional in coastal areas but were often susceptible to electrical interference in urban environments, which could disrupt the low-frequency radio signals. Signpost systemsFor vehicles operating on fixed routes, such as public transit buses or trains, signpost systems were an effective early solution. These systems used strategically placed transmitters, or "signposts," along a route. As a vehicle passed a signpost, a reader on the vehicle would receive a unique signal and transmit that event back to a central control system. This allowed dispatchers to track a vehicle's progress along its route and determine if it was on schedule. This method was particularly useful in tunnels or urban canyons where other radio signals were unreliable.[17] Advent of GPS and modern telematicsThe widespread availability and decreasing cost of the Global Positioning System (GPS) changed AVL technology. GPS provided far greater accuracy and global coverage than previous systems and was largely immune to the electrical interference that plagued earlier radio-based methods. The modern AVL standard quickly became a GPS receiver in the vehicle that communicates its location data back to a dispatch center via cellular (GSM/GPRS) or satellite networks. This shift made AVL technology more reliable and affordable, which led to modern telematics, where simple location tracking evolved to include a wide range of data points such as driver behavior, fuel consumption, and vehicle diagnostics.[18] This technology is now fundamental for managing large commercial fleets and providing mandated location data for emergency services like Enhanced 9-1-1. See also
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