Tachograph Analysis: What It Is, Why It Matters, and Whether You Need a System
Downloading tachograph data isn't compliance. Storing it isn't compliance either. The part DVSA actually cares about — and the part most small operators underestimate — is analysis: checking the data for infringements and acting on what you find.
This guide explains what tachograph analysis involves, why it's a legal expectation rather than an optional extra, and how to decide whether your operation needs dedicated software or can stay compliant with a disciplined spreadsheet routine.
General guidance, not legal advice. Tachograph and drivers' hours obligations vary by vehicle category and operation type. Always check the rules that apply to you against current DVSA guidance.
What Tachograph Analysis Actually Is
Tachograph analysis is the process of reviewing recorded driving data to confirm your drivers are staying within the legal limits — and to spot, record, and correct any breaches.
The raw data tells you when each driver was driving, resting, doing other work, or available. Analysis turns that raw record into answers to the questions that matter:
- Did anyone exceed the 9-hour daily driving limit (or the 10-hour extension, used no more than twice a week)?
- Did anyone drive more than 56 hours in a week, or more than 90 hours across two consecutive weeks?
- Did every driver take a 45-minute break after no more than 4 hours 30 minutes of driving?
- Did everyone get their 11 hours of daily rest (or a properly recorded reduced or split rest)?
- Are there gaps in the data where manual entries should have been made?
If you can't answer those questions from your records, you aren't analysing — you're just archiving. For the full set of limits these checks are based on, see our HGV driving hours guide.
Why Analysis Is a Legal Expectation, Not a Nice-to-Have
DVSA's tachograph guidance is explicit that operators must download data and "analyse the information to ensure that the rules have been complied with." Downloading without analysing leaves the legal duty half-done.
Two deadlines drive the download side of this:
- Driver card data must be downloaded at least every 28 days
- Vehicle unit (VU) data must be downloaded at least every 90 days
Once downloaded, the data must be kept for at least 12 months. But retention is the floor, not the obligation. The obligation is to act on what the data shows.
When DVSA visits an operator, "we download the data" is not a defence on its own. They want to see that you reviewed it, that you found infringements (everyone has some), and that you did something about them — a recorded conversation with the driver, a process change, retraining. An operator who downloads diligently but never reviews looks worse to a Traffic Commissioner than one who finds and fixes problems, because the first one is blind to their own risk.
What Counts as "Acting on the Data"
Finding an infringement isn't a failure. Ignoring it is. A defensible analysis process looks like this:
- Download on schedule — driver cards every 28 days, vehicle units every 90 days, and always before a driver leaves or a vehicle returns off lease.
- Review for the standard infringements — short daily rest, late breaks, over-limit driving, missing manual entries.
- Record what you found — date, driver, type of infringement, severity.
- Have the conversation — speak to the driver, note the discussion, agree a correction.
- Track patterns — a one-off short rest is human; the same driver short on rest every week is a systems problem you own.
That paper trail is what protects your O-licence if you're ever called to a public inquiry. It also keeps infringements off your OCRS score before they accumulate into an amber or red rating.
The Most Common Things Analysis Catches
Across small operations, the same issues surface again and again:
- Reduced daily rest taken too often — the 9-hour reduced rest is allowed only 3 times between weekly rests; a fourth is an infringement
- Breaks taken in the wrong order — splitting the 45-minute break as 30 then 15 doesn't comply; it must be 15 then 30 within the driving period
- Drifting over the daily limit — usually by 20-40 minutes, often because loading time was logged as driving
- Missing manual entries — gaps when a driver starts or ends away from the vehicle, or swaps vehicles mid-shift
- Overdue downloads — the 28-day driver card clock comes round fast for part-time and agency drivers
None of these are exotic. They're the bread-and-butter findings of any analysis routine — which is exactly why an operator who isn't analysing is almost certainly carrying infringements they can't see.
Do You Need Analysis Software?
This is the real question for a 1-5 vehicle operator. The honest answer: it depends on how many vehicles you run and how disciplined you are.
One vehicle, one driver (you). A spreadsheet and a calendar reminder can work. You're downloading one card and one VU, reviewing your own data, and you know your own shifts. Free or low-cost analysis tools bundled with some download devices are often enough at this scale.
Two to three vehicles. This is the tipping point. Manual analysis is still possible but gets unreliable — cross-checking break placement and rest reductions across multiple drivers by eye is error-prone, and the failure mode is silent (you miss infringements rather than getting an obvious error). Many operators at this size move to dedicated analysis software here.
Four to five vehicles or more. Manual analysis is no longer realistic. Dedicated tachograph analysis software that flags infringements automatically, tracks download due dates, and produces driver reports pays for itself in avoided penalties and reclaimed time. By this point you're also likely managing the data alongside broader fleet compliance software rather than a standalone tool.
A useful test: if you can confidently say, off the top of your head, when each driver's card was last downloaded and whether anyone has used three reduced daily rests this week, you're managing fine manually. If that question makes you uneasy, you've outgrown the spreadsheet.
What to Look For in a Tachograph Analysis Tool
If you decide you need software, the features that actually matter for a small operator are:
- Automatic infringement flagging against the current drivers' hours limits — not just data display
- Download due-date tracking for both driver cards (28 days) and vehicle units (90 days)
- Driver-level reports you can use for the recorded conversation
- Manual-entry gap detection so missing records surface before DVSA finds them
- Clear severity grading so you can prioritise — minor infringements vs serious ones
Avoid paying enterprise prices for fleet-of-100 features when you run five vehicles. Confirm current pricing directly with providers, and check whether the tool integrates with your download hardware so the workflow stays simple.
The Bottom Line
Tachograph analysis is the step that turns data collection into actual compliance. DVSA expects it, a Traffic Commissioner will ask for evidence of it, and your OCRS score reflects whether you're doing it. Whether you analyse with a spreadsheet or software depends on scale — but not analysing isn't an option for any operator running vehicles over 3.5 tonnes.
For a quick view of where tachograph analysis sits alongside your wider O-licence obligations, try our free O-Licence Compliance Health Check.