What does 49 CFR 392.33 (Obscured lamps or reflective devices/material) require?

Short answer

No commercial motor vehicle shall be driven when any of the lamps or reflective devices/material required by subpart B of part 393 are obscured. The exception is that the conspicuity treatments on the front end protection devices of the trailer may be obscured by part of the load being transported.

The rule says

"No commercial motor vehicle shall be driven when any of the lamps or reflective devices/material required by subpart B of part 393 of this title are obscured by the tailboard, or by any part of the load or its covering, by dirt, or other added vehicle or work equipment or otherwise." (49 CFR 392.33(a))

"Exception. The conspicuity treatments on the front end protection devices of the trailer may be obscured by part of the load being transported." (49 CFR 392.33(b))

In plain English

This rule means that drivers and motor carriers must ensure that all required lamps and reflective devices on their vehicles are visible and not blocked by anything, including cargo, equipment, or dirt. If any of these devices are obscured, the vehicle cannot be driven. However, there is an exception for the reflective material on the front of a trailer, which can be partially blocked by the cargo being transported.

What to do

• Check all lamps and reflective devices on the vehicle before driving to ensure they are not obscured.
• Clean or adjust any devices that are blocked by dirt or equipment.
• Verify that cargo is properly secured and does not block any required lamps or reflective devices.
• Ensure that all drivers are aware of and comply with this regulation to avoid potential safety hazards and regulatory issues.