A bus driver wants to prevent arguments later in the trip over smoking, drinking, or radio/tape player use. According to the manual, when should the driver explain these carrier rules to riders?

49 CFR 383.117(a)(6), operating practices and procedures not otherwise specified; AAMVA CDL Manual Section 4.3.1 (p.4-2)

Stating the ground rules before the bus even leaves the stop heads off most mid-trip disputes before they start. This kind of judgment call falls under the federal passenger-endorsement test's catch-all "general operating practices" topic, since not every situation a driver faces has its own numbered regulation.