The four activity modes
Under the assimilated drivers’ hours rules a driver must use the tachograph "to record driving time, breaks and rest periods, periods of other work and periods of availability", and DVSA’s guide requires that "through the daily working period the mode button is used correctly to record other work, periods of availability, and rest and breaks". The four modes, with the regulation’s pictogram names, are:
| Mode | Pictogram | What it covers | Set by |
|---|---|---|---|
| Driving | A steering wheel | Time at the wheel with the vehicle moving. Counts towards the 4.5-hour, daily, weekly and fortnightly driving limits. | Automatic on digital and smart units as soon as the vehicle moves |
| Other work | Two crossed hammers | "All activities defined as work other than driving in scope of assimilated or AETR rules. Includes any work for the same or another employer, within or outside the transport sector": loading, checks, paperwork, a second job. | The mode switch; also the default on many units when the vehicle stops |
| Availability (POA) | A square with a diagonal slash | "Periods of waiting time, the duration of which is known about in advance", when the driver is not required to stay at the workstation: waiting for a known loading slot, accompanying the vehicle on a ferry crossing, sitting as second driver. | The mode switch |
| Break or rest | A bed | Time used exclusively for recuperation, with no driving and no other work. A break may be taken in a moving vehicle only if no other work is done. | The mode switch |
Two rules follow. Waiting of unknown length is other work, not POA, because POA has to be known in advance. And a "break" during which you tidy the load or answer work emails is other work, whatever the switch says; DVSA reads the whole day, not just the symbol.
Specific conditions: out of scope and ferry/train
The regulation lists two "specific conditions" with their own pictograms.
- Out of scope (OUT). Sets the unit to record without applying the assimilated rules: driving that is genuinely outside them, such as a wholly off-road journey or a vehicle on an exempt operation. DVSA’s guide is strict about the limits: "journeys that are made entirely off road are out of scope of assimilated drivers’ hours and tachograph rules. However, under assimilated and AETR rules on record keeping, drivers who carry out any work regulated under these rules must record all periods of off-road driving as ‘other work’." Any driving in scope during a day brings the whole day in scope, so OUT is not a way to hide a short in-scope leg.
- Ferry/train crossing. Tells the unit that a daily rest is being interrupted by embarking or disembarking. The concession is narrow: a regular daily rest "may be interrupted no more than twice by other activities of not more than 1 hour’s duration in total, provided that the driver is accompanying a vehicle that is travelling by ferry or train and has access to" a bunk or couchette. The flag records the interruption so the rest still counts as regular.
Cards, slots and people
The pictogram appendix groups symbols by who or what they represent. On the display and printouts you will see: a driver figure (driver, slot 1), a second figure (co-driver, slot 2), and the four card types, driver, company, control (enforcement) and workshop, plus a crossed card for "no card". A card symbol next to a slot means a card is inserted there; the "insertion" and "withdrawal" events are recorded with the time. DVSA’s rule on the card: "use only their own personalised driver card to record driving and other activities they undertake" and "ensure that the card is not removed from the tachograph during the working day unless otherwise authorised", the recognised cases being a change of vehicle or another driver taking over.
Events and faults
An exclamation mark inside a triangle marks an event; a spanner marks a fault. The events the regulation defines include driving without a valid card, card insertion while driving, a time overlap between two cards, a power supply interruption, a motion data error, and over speeding. Most events are recorded silently and appear on the "events and faults" printout that a DVSA examiner or a company download will pull. A fault symbol that stays lit is a defect: the unit or sensor needs a tachograph centre, and until then the driver records activities by hand on a printout or temporary sheet.
Warnings you will see while driving
- Continuous driving time (steering wheel with a clock): most units warn the driver as continuous driving approaches and reaches 4 hours 30 minutes without a qualifying break; the duty to stop is yours whether or not the warning sounds. What counts as a break, and the 15 plus 30 minute split, is on the drivers’ hours page.
- Over speeding: the unit records any period above the set threshold; the "over speeding printout" lists them. The limits themselves are on the HGV speed limits page.
- Position after 3 hours accumulated driving: a smart 2 unit records its GNSS position automatically every three hours of driving; the pictogram appears on the printout rather than as a warning.
Manual entries
The "manual entry of driver activities" pictogram (a hand writing) covers everything the unit could not record itself: work done since the card was last removed, a rest day, a period in a vehicle without a tachograph. When you insert the card the unit asks whether you want to add activities for the gap; answer it truthfully, because the alternative is a record showing you did nothing. DVSA’s guide also requires a manual record when the mode switch was set wrongly: "the driver must make a manual tachograph record to this effect. For digital or smart tachographs, the driver should make and sign a printout for the relevant period with a note giving details of the error and reason at the time the error is made." Records for rest days and leave are required too.
Reading a printout
The daily printout from the card (driver activities from card) and from the vehicle unit both use the same pictograms in the same order: the header with the card and vehicle identifiers; a line per activity with its start time, duration and mode symbol; the "24h" qualifier for a daily total; "weekly" and "two weeks" for the driving totals against the 56 and 90 hour limits; the location symbols for the start and end of the daily work period; then any events and faults. Time on printouts is UTC unless the unit has been set to local time, which is why a printout can appear to start an hour before you did.
What you must be able to produce
At the roadside a driver must be able to produce "charts and any legally required manual records for the current day and the previous 28 calendar days for AETR or domestic journeys under the assimilated rules or 56 days for international journeys to and from an EU member country", together with the driver card. Operators must download the vehicle unit at least every 90 days and driver cards every 28 days and analyse them. Where a card is lost, stolen or faulty, driving may continue for up to 15 calendar days on printouts taken at the start and end of each day, with a replacement applied for within seven days: see the driver card page.
Common mistakes
- Leaving the unit on "other work" through a break, which turns a legal day into a breach of the 4.5-hour rule on paper.
- Using POA for waiting whose length was not known in advance.
- Using OUT for an in-scope leg because it was short.
- Skipping the manual entry prompt at card insertion.
- Removing the card at lunch so the vehicle can be moved by someone else without their card.
Units are fitted, calibrated and repaired only at DVSA-approved centres: find one in the tachograph centre directory. The rules the symbols serve are on the drivers’ hours page, and the drivers’ hours calculator works your day from them.