The tachograph, often called the 'spy in the cab', is a device that records driving and rest times for professional drivers of commercial vehicles.

Its primary purpose is to enforce social regulations (like EC Regulation 561/2006) designed to ensure driver safety, prevent fatigue, and guarantee fair competition within the transport industry.

There are two main types: 1.

**Analogue Tachograph:** The older system, which records data by cutting lines onto a circular paper chart (a 'tacho disc').

Each disc holds 24 hours of data.

2.

**Digital Tachograph:** The modern standard, mandatory in new vehicles since 2006.

It records data digitally onto its internal memory and onto a personal 'driver card' inserted by the driver.

The device records different statuses: 'driving' (when the vehicle is moving), 'other work' (like loading/unloading), 'availability' (e.

g.

, waiting), and 'rest/break'.

This data must be regularly downloaded and stored by the company and can be inspected by authorities during a roadside check.

Failure to comply with tachograph rules can lead to severe fines.