Every digital tachograph speaks the same visual language: a small set of pictograms that record what the driver is doing at any moment. Drivers who learned the symbols years ago and never revisited them are one of the most common sources of mode-selection errors DVSA finds - and mode errors are hours errors, so the symbols are worth a refresher.
The core symbols represent the four activity modes the tachograph can record.
The driving symbol - a steering wheel - records driving time. On most tachographs this mode is selected automatically whenever the vehicle moves, which is exactly as it should be: driving is the one mode the driver must never have to remember to choose.
The other work symbol - crossed hammers - covers all working time that is not driving: loading and unloading, cleaning and maintenance, paperwork for the job, waiting where the driver must remain at the workstation and work. The guidance is explicit that ‘other work’ means all activities defined as working time under the rules except driving, including any work for the same or another employer, in or out of the transport sector.
The availability symbol - a square with a diagonal line or, on some units, a stylised seat - is the period the driver must be present and ready but need not work: the classic cases are time spent travelling as a passenger next to the driver in a moving vehicle, time on a ferry or train, and waiting at borders or during loading where the driver is not required to work but must stay available. Availability matters because it counts differently for working time purposes than other work does.
The rest or break symbol - a bed - is for breaks and rest: any uninterrupted period during which the driver can freely dispose of their time. The test is freedom, not location. Time spent in the cab waiting for a bay where the driver must stay with the vehicle is not rest; time where the driver is free to leave and use the time as they wish is.
Mode selection is not cosmetic. The recorded mode feeds every downstream calculation: driving-time limits, break requirements, working time totals, and the analysis your operator’s tachograph software runs. A driver who leaves the unit on ‘other work’ while genuinely on break has shortened their own legal break in the record; one who sits on ‘break’ while strapping a load has created an hours offence in the data. Both are visible to DVSA, and both generate the kinds of infringement reports that end with interviews.
The practical discipline: select the mode deliberately at every activity change, and check the display when you stop and when you set off. Vehicle movement will force driving mode automatically, but the return journey into the yard, the wait at the bay and the walk-round all need conscious choices.
One symbol rule catches even experienced international drivers. Unless the smart tachograph does it automatically, the driver must record the country symbol of the country entered when a border is crossed, at the first suitable stopping point at or after the border. When crossing a border on a ferry or train, the symbol must be recorded at the port or station of arrival.
That entry creates the location trail enforcement uses to reconstruct the journey, and missing country entries are a standard finding in international operations checks. If you drive a vehicle with a smart tachograph that records position automatically, the duty adjusts - but ‘the unit does it’ is only safe if you know your unit actually does it.
Beyond the four driver modes, the symbols extend to who is using the unit: the workshop mode for calibration and testing by approved centres, the control mode for enforcement officers reading data, and the company mode an operator uses to lock in and lock out data so records belong to the right operator. Drivers meet these rarely, but recognising them explains the odd displays that appear when a workshop or an examiner has been connected.
The whole of tachograph symbol literacy reduces to a habit: glance at the unit when the activity changes, choose the mode that matches what you are actually doing, and record the country symbol at borders when the unit does not do it for you. Four pictograms, one border rule, zero excuses at the roadside.