Where a driving record breaks the rules, and exactly when TACHO

The rules are not complicated so much as unforgiving

Tachograph analysis is sold as a subscription, and most of what it does is arithmetic anybody could do. What makes it hard is not the sums. It is that nearly every rule has an exception with a counter attached to it, and the counter is what people lose track of over a fortnight.

• Four and a half hours of driving needs a forty-five minute break, or a fifteen and then a thirty, in that order. Thirty then fifteen does not count, and a great many drivers believe it does.
• Nine hours of driving in a day, ten twice a week. Twice. Not twice a day, and not three times in a week that happened to be busy.
• Eleven hours of daily rest, reducible to nine, three times between weekly rests. Again a counter, and again one nobody tracks in their head.
• Forty-five hours of weekly rest, reducible to twenty-four, with the shortfall to be compensated as a block attached to a rest of at least nine hours within the next three weeks, and the compensation is the part that is forgotten, because it falls due long after the week that caused it.

So the counters are the tool. The arithmetic of a single day is easy; knowing that this is your third reduced daily rest and your second ten-hour day is the thing that stops an infringement.

Why it is done here, on a record you type in

A driver's record is personal data about a named, identifiable person, and it is also a record of exactly where they were and when for weeks at a time. It is among the more sensitive things a small operator holds, and the ordinary way to check it is to upload it to a service.

This runs in the tab, so you can check a record without it going anywhere, which is useful for a driver checking their own week before an inspection, for an operator working out whether an infringement happened before deciding what to do about it, and for anybody who would rather not add a processor to their register for a calculation.

The honest limit is the other side of that: it works from what you type in. It does not read a card or a vehicle unit, so it cannot tell you that the record itself is wrong: a missing card, a manual entry that does not match, an other-work period recorded as rest. Those are found by reading the download, and they are the ones that matter most in an investigation.

Use it as a check, not as a defence

A clean result here means the record you entered complies with the rules as implemented. It is not a legal opinion, it does not know about your national derogations or your domestic rules, and it does not know whether the Working Time rules (which are separate, and which catch people who are comfortably legal on drivers' hours) are satisfied.

Where it earns its keep is before the week happens. Running the plan through it on a Monday tells you that Thursday's schedule needs a reduced rest you have already used twice, while there is still time to change the schedule. Found on Thursday, the only options left are an infringement or a late delivery.

Nothing is uploaded. Nearby: CONVOY for a run with more than one vehicle, the guide to rest runs and the rolling week for how the counters interact, TIMESHEET for what the hours come to, and MILEAGE for the claim afterwards.