Different requirements by state

95% of all the critical aspects of trucking with regards to rules are uniform across all states. The odd and abnormal rules such as california bridge/length law are minimal and don't typically cause any problems in other states. i.e they are the highest common denominator with regards to restrictions. (if you load in MA for CA, and get legal weight/length wise for CA in MA, you'll be good all the way across.

The carriers work to keep their drivers informed of key rules that may change, but all in all it's no big deal outside of oversize load driving rules/regs. This is the short answer to your question.