Digital vs. analogue tachograph – what are the differences

How an analogue tachograph works

An analogue tachograph writes with a stylus onto a paper chart inserted into the device for 24 hours. Before setting off, the driver writes on it by hand their name, the date, the place of departure and the odometer reading.

The record is produced mechanically – three traces on the chart show speed, distance covered and the driver's activity. Switching between driving, other work, availability and rest is done with a lever on the device.

Reading such a record is a craft. An inspector or transport technician has to assess the chart visually, which is slow and leaves room for interpretation.

How a digital tachograph works

A digital tachograph replaced the chart with a smart driver card. The driver inserts it into the device and everything else is recorded electronically – onto the card and into the memory of the vehicle unit.

The data is later downloaded into DDD files, which are digitally signed. The signature is the fundamental difference: it can be verified that nobody has tampered with the contents.

The record is also more complete. Besides the driver's activities, the device logs events and faults – a power interruption, driving without a card or an attempt at tampering.

What the difference means in practice

Credibility. A paper chart is a physical object – it can be lost or damaged, and assessing it depends on how legible the trace is. The digital signature on a DDD file closes that discussion.

Effort. With an analogue tachograph you collect and archive charts, one for each day and driver. With a digital one, the card is downloaded once every 28 days and the unit once every 90.

Range of data. A digital tachograph records things a chart cannot capture – for instance who drove the vehicle before you, or that somebody attempted to interfere with the device.

Accuracy. A mechanical trace has a resolution fixed by physics. An electronic record is more precise and does not depend on the state of the stylus or on how the chart was stored.

Where an analogue tachograph may still be used

Analogue devices have not disappeared from operation, but their scope has narrowed substantially. In international transport they are no longer enough – those vehicles had to be retrofitted with a second-generation smart tachograph by 31 December 2024.

What remains is mainly domestic transport with older vehicles that do not cross borders. If you have such a vehicle and it operates exclusively at home, the retrofitting obligation does not affect it.

The moment it is due to head across the border, however, the situation changes. So it pays to know in advance which vehicles in the fleet are "domestic only" and which are not – this cannot be improvised.

What it means for archiving

With an analogue tachograph you archive physical charts. They must be legible, stored so they do not deteriorate, and traceable by driver and date.

With a digital one you archive DDD files. They are kept for at least twelve months after being recorded and, at the request of an inspecting officer, must be accessible either directly or remotely at the premises of the undertaking – so an archive on a memory stick in a drawer does not meet that requirement.

One rule applies equally to both worlds: the record is not edited. On a chart it would be visible; on a DDD file it would destroy the digital signature that is its entire value.

And where GPS fits in

GPS tracking is a third, separate layer – and it is a replacement for neither of them. A GPS unit is not an approved recording device under Regulation (EU) No 165/2014, so a statutory record of driving times cannot be produced from it.

What it does address is what the tachograph does not: a mileage log for tax purposes, real-time vehicle positions, costs and route planning.

Companies operating vehicles under Regulation 561/2006 therefore generally need both – the tachograph for transport rules and GPS for records and day-to-day operations.