The regulations assign duties to named roles, and § 390.5T defines each more broadly than its everyday sense. Chapter 1 introduced two of them — driver and employer — to establish who the rulebook is addressing; the set is larger than two, and the roles it did not name are where the surprises sit. An employee is any individual, other than an employer, employed by an employer who in the course of that employment directly affects commercial motor vehicle safety; the definition expressly includes a driver, a mechanic and a freight handler, and expressly includes an independent contractor while in the course of operating a commercial motor vehicle. Motor carrier covers a for-hire or private carrier together with its agents, officers and representatives, and for the purposes of this subchapter the term includes employer and exempt motor carrier — so a duty written for a motor carrier reaches all three. An exempt motor carrier, despite the name, is one exempt from economic regulation and expressly still subject to the safety regulations set out in this subchapter.

Two of those definitions carry a sting. The independent contractor clause means that operating under your own authority does not put you outside the employee definition while you are at the wheel. And the exclusion in both the employee and employer definitions is for government — the United States, a State, a political subdivision of a State, or an agency established under an approved interstate compact — not for small operators. Being a one-truck business is not an exemption from anything.

§ 390.3T(f) then excepts certain operations from subchapter B altogether, unless otherwise specifically provided. They include all school bus operations, save for a short list of sections that continue to apply; transportation performed by the Federal government, a State, a political subdivision, or a Congressionally approved interstate compact agency; the occasional transportation of personal property by individuals, not for compensation and not in furtherance of a commercial enterprise; the transportation of human corpses or sick and injured persons; and the operation of fire trucks and rescue vehicles while involved in emergency and related operations. Read these as exceptions from the safety regulations only. § 383.3(b) already made the point that they do not reach the license rules, and several of them carry named carve-backs that keep specific sections in force.