Would the maximum penalty be if you had, say, failed a drugs/drink test, or been racing or something like that (reckless rather than careless)?
There's a whole lot of law around "dangerous", "careless" and "reckless". ("Caldwell recklessness" from my study days).
There comes a point at which "carelessness" doesn't cut it, and "reckless" takes over. At the end of the spectrum you have "dangerous" which excludes the other two.
"Dangerous" isn't "careless", nor "reckless". It's dangerous. That is behaviour so obviously dangerous there can be no other excuse for it.
It can get very complicated very quickly ... which is why we have courts and experts to deal with it.