Driver card files
Review driving, other work, POA (period of availability), breaks, rest, manual entries and unknown periods across day, week, timeline and calendar views. Supported by Driver and Business.
Online tachograph file viewer
Open a .DDD file and understand what it contains.
It opens in your browser — nothing to install. Use TachoAssist as a browser-based tachograph file viewer for driver cards and vehicle units, then move from .DDD source records to activity, infringements and reports. It also reads .esm, .tgd, .c1b, .v1b and .a1b files, and ZIP archives when you have a batch of them.
What is a .DDD tachograph file?
A .DDD file is an original download from a digital tachograph driver card or a vehicle’s tachograph unit. Specialist software is needed to translate the signed records into something a driver or operator can review.
TachoAssist keeps the source file connected to its analysis. It is more than a raw tachograph file reader: you can follow activity, investigate infringements and create evidence for a chosen period — without a desktop install, a licence key or an IT ticket.
Two file types, two different views.
The file source determines which records are available and which plan is required.
Vehicle unit (VU) files
Review vehicle identity, detected drivers, events, faults, downloads, odometer records and recorded locations. Supported by Business.
Original file history
Keep uploads tied to their source, review file history and manage retention, deletion or archiving from the same workspace.
Supported files
Every extension the same data arrives under.
The UK downloads .DDD almost exclusively, but the same tachograph records travel under different extensions elsewhere in Europe, and a mixed fleet or an agency driver’s card can turn any of them up.
Extensions
.ddd (UK, Germany, most of Europe), .esm, .tgd (Spain), .c1b and .v1b (France — card and vehicle), .a1b. TachoAssist reads all of them.
ZIP archives
Drop in a ZIP straight from the download key or the bureau and the files inside are unpacked and analysed together, rather than one at a time.
Signature and completeness
The records are digitally signed at source. If a file is truncated or the expected days are not in it, that shows up as missing data to investigate — it is not quietly filled in.
Retention still sits with you
Opening a file online does not transfer the duty. Tachograph records must be available for at least 12 months, Working Time (WTD) records for two years. Keep the originals.
From file viewer to practical review.
- Readable activity timelines and monthly calendars
- EU and assimilated GB drivers’ hours infringements
- Working Time (WTD) and tachograph-rule infringements, with severity and the legal reference
- Indicative fine estimates for work in the 27 EU member states
- Driver, selected-driver, fleet and vehicle reports
- PDF and Excel output for Business users
Important: automated infringements support compliance work and must be reviewed. They are not legal advice or a definitive statement of compliance.
Continue with the task you need.
Questions
.DDD file viewer FAQ
What program opens a .DDD file?
TachoAssist opens driver card and vehicle unit .DDD files in a modern web browser and presents their tachograph records as readable analysis rather than raw file data. There is nothing to install and no desktop software to license.
Do I have to install anything to open a .DDD file?
No. The viewer runs in the browser you already have, on Windows, macOS, Linux, a tablet or a phone. Register, upload the file and the analysis appears; nothing is installed on the machine and there is no IT involvement.
Which tachograph file formats are supported?
Alongside .ddd, TachoAssist reads .esm, .tgd, .c1b, .v1b and .a1b files, which are the extensions used by different national authorities and download devices for the same underlying tachograph data. You can also upload a ZIP archive containing several files at once.
Are driver card and vehicle unit .DDD files the same?
No. A driver card file centres on one driver’s activities and card records. A vehicle unit (VU) file contains vehicle tachograph records such as identified drivers, events, faults and recorded positions. Reviewing both together is what shows the full picture.
Can a .DDD file be turned into a PDF or Excel report?
Yes. TachoAssist can use uploaded tachograph records to generate reports for selected date ranges. Business reporting supports PDF and Excel outputs.
Does opening the file online replace keeping the original?
No. The retention duty stays with the operator: tachograph records must be available for at least 12 months, and Working Time (WTD) records for two years. TachoAssist keeps uploads tied to their source file with history, retention, deletion and archiving controls, but the obligation is yours.
Where does a .DDD file come from, and do I need hardware to make one?
TachoAssist sells no hardware. The free TachoAssist Card Reader app turns any standard USB smart-card reader into a driver-card download tool on Windows or Android, free and with no account needed to read and save the file. Vehicle unit data still comes from your download key or remote download.