When establishing a pavement reference marking system (PRMS), which rule establishes left and right of the centerline when facing away from the runway zero point?

• A. Letter
• B. Left/Right
• C. Centerline
• D. Zero point

Answer: (D)

In a pavement reference marking system, you need a fixed origin to keep everything oriented the same way as you move along the pavement. That fixed origin is the runway zero point. The rule that determines how left and right are defined when you’re looking away from that point is the zero point rule. It sets a single reference so, no matter where you are, left and right are interpreted consistently from the perspective of facing away from the zero point.

Why this is the best answer: the zero point serves as the origin for all orientation decisions in PRMS. Without a defined zero point, the terms left and right could become ambiguous as you move along the centerline. The other options either refer to labeling or to the feature itself, not to the rule that standardizes the directionality relative to the origin.