Noun
tachograph (plural tachographs)
A device that records the distance and time traveled by a vehicle (especially a truck or coach), used to check the drivers' working time.
Synonym: tacho
Hypernym: black box
A professional driver is required to insert his driver's license into a digital tachograph before starting to drive. Source: Internet
The tachograph unit records speed violations for each driver and gives a printed report. Source: Internet