An IVMS (In Vehicle Monitoring System) combines the installation of an electronic device in a vehicle, or fleet of vehicles, with purpose-designed computer software at least at one operational base to enable the owner or a third party to track the vehicle's location, collecting data in the process from the field and deliver it to the base of operation. Modern vehicle tracking systems commonly use GPS technology for locating the vehicle, but other types of automatic vehicle location technology can also be used. Vehicle information can be viewed on electronic maps via the Internet or specialized software.
Several types of vehicle tracking devices exist. Typically they are classified as "passive" and "active".
"Passive" devices store GPS location, speed, heading and sometimes a trigger event such as key on/off, door open/closed. Once the vehicle returns to a predetermined point, the device is removed and the data downloaded to a computer for evaluation. One such example of a passive device would be a GPS Log Book that gathers the data and stores it for later upload
"Active" devices also collect the same information but usually transmit the data in real-time via cellular or satellite networks to a computer or data center for evaluation. The information is typically analysed and presented using web based technologies.
Many modern IVMS devices combine both active and semi-passive tracking abilities: when a cellular network is available and a tracking device is connected it transmits data to a server; when a network is not available the device stores data in internal memory and will transmit stored data to the server later when the network becomes available again. So, although the actual upload is Active, there is a time delay between the time the position is recorded and the time it is sent back-to-base, making the units semi-passive. Where IVMS is used to drive driver safety and improve on general driver behaviour, this makes no difference in reality: data gets uploaded (delayed) but is still available for post-processing purposes, so overnight safety reports are not affected by this provided the vehicle comes back into coverage later during that day.
Historically IVMS has been accomplished by installing a box into the vehicle, either self-powered with a battery or wired into the vehicle's power system. For detailed vehicle locating and tracking this is still the predominant method; however, many companies are increasingly interested in the emerging cell phone technologies that provide tracking of multiple entities, such as both a salesperson and their vehicle. These systems also offer tracking of calls, texts, Web use and generally provide a wider safety net for the staff member and the vehicle.
IVMS Units track many different types of activity within a vehicle such as GPS Position, Various inputs such as seatbelt and 4x4 engagement, Speed, Impact/Rollover, Harsh events (acceleration and deceleration, usually performed by a Triaxial Accelerometer) over revving, excess idle time just to mention a few.
The implementation of IVMS often has significant cost savings: by getting drivers to slow down and drive more carefully, stress is also taken off vehicles. This in the end has savings not only in terms of fuel, but also in terms of general vehicle wear-and-tear like brake pads and disks and engine wear.