If it's on the internet & you can find it, without having to "hack" into something, then it's legal.
Not sure if I understand your question though. Are you asking if it's illegal for ANYONE to get the information, ... or if it's legal to get the information ABOUT anyone?
I know it's legal if you're looking up a trucking company or an independent O/O. Looking up an individual driver's history is also legal, but will probably cost money, unless that person you're looking up is yourself.