Truckers need $750k of liability insurance (but usually have $1M). For individual drivers, they are required to have liability, but it varies by state (and in some places a lot of people flaunt the law).
That is shockingly low. My normal car insurance without any extra add-ons covers up to £20 million($26 million) in 3rd party damage, and I believe EU mandates that every car insurance, no matter how cheap, has to provide at least 5 million euro cover. So even the most basic, 3rd-party-only, shit car insurance has to cover you for up to 5 million euro, by law.
Outside of trucking: In the US, there are a handful of States that do not even require car insurance, and in the ones that do require it, the minimum "shit tier" coverage is astoundingly low. In Florida, where I once lived, you could get coverage of $10K (property damage and personal injury) and be driving legally. $10K won't even cover the cost of a broken leg.