What element is considered essential when performing a head check?

The element considered essential when performing a head check is looking over your shoulder. This action is crucial because it allows the driver to visually confirm that the area beside and behind the vehicle is clear of pedestrians, cyclists, or other vehicles that may not be visible in mirrors. While rearview mirrors provide a general view of what's behind, they cannot capture blind spots, which is why physically turning your head provides additional safety and awareness.

The other elements, such as checking rearview mirrors and signaling intent, are important components of safe driving overall, but they do not specifically address the need to clear blind spots that could lead to collisions when changing lanes or merging. Adjusting your seat is also important for ensuring comfort and control while driving, but it is not relevant in the context of executing a head check before making a maneuver.