Which statement describes a TDR awareness indicator?

• A. Green light, door lock engaged.
• B. Flashing red and green, door lock not engaged.
• C. Green TDR indicator (green paper).
• D. Dock plate in place.

Answer: (A)

TDR awareness indicators show when the trailer is safely restrained to the dock and ready for safe access. The best indicator is a solid green light with the door lock engaged. That combination confirms the truck dock restraint is latched and the trailer is secured, preventing movement while workers open or unload. If the signal is a flashing red and green with the door lock not engaged, the trailer isn’t secured yet, which is unsafe. A green indicator on its own or a green paper tap might not reliably confirm the system is fully engaged, and the dock plate being in place speaks to bridging the gap rather than the security of the trailer. So the solid green light with the door lock engaged is the clear sign that it’s safe to proceed.