May the ‘‘park’’ position of a CMV’s transmission be used as a parking brake to comply with the § 393.41?

Section § 393.41: Parking brake systems.

Question 1: May the ‘‘park’’ position of a CMV’s transmission be used as a parking brake to comply with the § 393.41?

Guidance: No. The ‘‘park’’ position of the transmission is only a locking device used to lock...

May a system such as ‘‘driveline brakes’’ be used as an emergency brake provided it complies with the requirements of § 393.52?

Section § 393.40: Required brake systems.

Question 1: May a system such as ‘‘driveline brakes’’ be used as an emergency brake provided it complies with the requirements of § 393.52?

Guidance: Yes. CMVs which were not subject to the emergency brake...

Must all trailers be equipped with overload protective devices?

Question 2: Must all trailers be equipped with overload protective devices?

Guidance: No. Trailers do not need overload protective devices when protection of trailer circuits is provided on the towing vehicle. A circuit breaker should be used only when the head lamp...

Does a frame channel of a CMV constitute a protective ‘‘sheath or tube’’ as specified in §393.28?

Section § 393.28: Wiring systems.

Question 1: Does a frame channel of a CMV constitute a protective ‘‘sheath or tube’’ as specified in §393.28?

Guidance: No. To be acceptable, a sheath or tube must enclose the wires throughout their circumference. In the...

What are the lighting requirements when a container assumes the structural requirements of a trailer?

Section § 393.25: Requirements for lamps other than head lamps.

Question 3: What are the lighting requirements when a container assumes the structural requirements of a trailer?

Guidance: All relevant requirements of the regulations must be met by this...

Are there any special lighting requirements for large containers?

Section § 393.25: Requirements for lamps other than head lamps.

Question 2: Are there any special lighting requirements for large containers?

Are lighting devices on mobile homes/house trailers required to be permanently mounted?

Section § 393.25: Requirements for lamps other than head lamps.

Question 1: Are lighting devices on mobile homes/house trailers required to be permanently mounted?

Guidance: No. The movement of mobile homes/house trailers is considered to be a driveaway-...

Must additional lamps that are not required be operative if all required lamps are operative?

Section § 393.24: Requirement for head lamps, auxiliary driving lamps and front fog lamps.

Question 1: Must additional lamps that are not required be operative if all required lamps are operative?

What are the lighting requirements when a tow truck is pulling a wrecked or disabled vehicle?

Section § 393.17: Lamps and reflectors – combinations in driveaway-towaway operation.

Question 1: What are the lighting requirements when a tow truck is pulling a wrecked or disabled vehicle?

Guidance: A wrecker pulling a vehicle would be considered...

Footnote 5, requires that each converter dolly be equipped with turn signals at the rear

Section § 393.11: Lamps and reflective devices.

Question 3: Section § 393.11, Footnote 5, requires that each converter dolly be equipped with turn signals at the rear if the converter dolly obscures the turn signals at the rear of the towing vehicle when towed...