02

Who the rules cover

Chapter 1 drew the interstate line at a glance. This chapter is where it is decided in practice — what interstate commerce actually means, what state law can and cannot add, which vehicles the definitions reach, and who is excepted.

In this chapter

• +What interstate commerce means in the rule’s own three branches — and why a trip that never leaves your state can still be one
• +What a state may add on top of the federal rules, and what it may never take away
• +Which vehicles each definition reaches, and who the rules except entirely