Final answer:
A displaced threshold on an instrument runway is marked by a series of white arrows that lead up to a thick white line across the runway, indicating where aircraft should not land before reaching it.
Step-by-step explanation:
Runway markings that indicate a displaced threshold on an instrument runway are a series of longitudinal white stripes arranged in a pattern similar to piano keys. This area of the runway pavement, which precedes the actual landing threshold, is usable for taxiing, takeoff, and rollout from a landing, but not for touchdown during an approach to land. The presence of a displaced threshold can be for various reasons such as noise abatement, obstacle clearance, or runway construction.
The markings for a displaced threshold consist of white arrows leading up to the threshold marking itself, which is a thick white line stretching across the width of the runway. These white arrows provide a visual cue to the pilot that landing aircraft must not touch down before the thick white line. After the threshold markings, the runway continues with the usual runway centerline, aiming points, and touchdown zone markings.