tachograph

A tachograph is a device fitted to commercial road vehicles to record driving time, rest periods, and other activities. Its purpose is to ensure compliance with drivers’ hours rules, promote road safety, and support fleet planning and enforcement by authorities. The data collected can be used for audits, pilot fatigue management, and dispute resolution.

There are two main types of tachographs: analogue and digital. Analogue tachographs are mechanical devices that record data on circular chart disks as the vehicle moves. A stylus traces driving activity and speed onto the chart, which is replaced at set intervals, typically daily. Digital tachographs are electronic systems that store data directly in the vehicle unit, with separate driver and company cards used to identify individuals and operators. Data can be downloaded, stored, and analyzed by authorities and fleet managers.

In operation, a tachograph records driving time, breaks, and rest periods to verify compliance with applicable limits. It may also capture vehicle speed and distance traveled. Digital systems use cryptographic controls and tamper-evident seals to protect data integrity, while analogue systems rely on physical charts and seal mechanisms. Both types require regular inspection, calibration, and maintenance to ensure accuracy.

Regulatory framework varies by region but commonly mandates that tachographs be installed in certain heavy vehicles, that data be available for inspection, and that tampering be prohibited. In the European Union, regulations governing driving time and rest periods influence tachograph use, with similar aims in other jurisdictions.