49 C.F.R. § 374.313 Equipment.
Title 49 - Transportation
(a) Temperature control. A carrier shall maintain a reasonable temperature on each bus (except in commuter service). (b) Restrooms. Each bus (except in commuter service) seating more than 14 passengers (not including the driver) shall have a clean, regularly maintained restroom, free of offensive odor. A bus may be operated without a restroom if it makes reasonable rest stops. (c) Bus servicing. Each bus shall be kept clean, with all required items in good working order.
Title 49: Transportation
PART 374—PASSENGER CARRIER REGULATIONS
Subpart C—Adequacy of Intercity Motor Common Carrier Passenger Service
§ 374.313 Equipment.