Legally, no. Practically, yes.

Aren't tachographs or other logging means mandatory as in EU ?

If you're from the EU, you can probably already guess the answer to that question for the land of "don't tread on me" :-p

This is a rather unhelpful response given that I'm not sure many would guess correctly. Paper books have been used in the US for decades and electronic devices were made mandatory for most drivers (>8 days out of 30, apparently). Canada is now planning to emulate the US regulations on this.

> An ELD is an Electronic Logging Device that became compulsory in 2017 in the US for commercial driving operations required to keep hours of service records. If a driver has eight or more days worth of duty status logs (out of 30) they will be required by law to use an ELD.

https://www.optac.info/uk/eld-vs-tachograph/

https://www.fmcsa.dot.gov/hours-service/elds/eld-fact-sheet-...

The legislation linked is not about enforced breaks for drivers, though. Does the US have this?

Yes.

https://www.fmcsa.dot.gov/regulations/hours-service/summary-...

Cool, didn't know that, kind of surprising that the US would regulate this, knowing their general stances.

The conditions are quite harsh, compare them with this:

https://europa.eu/youreurope/citizens/work/work-abroad/rules...

Well, it's still far from EU, but it's something. Although rest times are VERY short.

US:

  - max 11h driving after 10h of rest (that sums 21h, so I guess you can drive 14h a day)
  - rest 30min every 8h of uninterrupted driving
  - max 60h driving a week

EU:

  - max 9h driving a day (10h driving allowed twice a week)
  - rest 45min every 4.5h of uninterrupted driving
  - max 56h driving a week. max 90 every two weeks.

Once you are switched to ELD's in the US, it is more difficult (compared to paper log books) to cheat enforcement [1].

[1] https://en.wikipedia.org/wiki/Hours_of_service#Enforcement

Yes, electronic logs are mandatory in the US.