Which turnabout maneuver is considered the most hazardous?

The Y turn is considered the most hazardous turnabout maneuver primarily due to its complexity and the amount of space required. This maneuver involves making a sharp turn in a tight space while carefully navigating around obstacles, which can increase the risk of collisions or loss of control. The driver's focus must be split between multiple directions, evaluating oncoming traffic, and any potential hazards nearby.

In contrast, while the U turn and K turn can also present challenges, they are generally performed in more straightforward situations where visibility and space are better managed. The U turn typically uses a wider area to make the turn, making it less hazardous in terms of immediate risk. The parallel turn, while requiring skill in alignment to parallel park, does not carry the same level of risk associated with navigating back onto a path after an aggressive turn as seen with the Y turn.

Thus, the Y turn's intricacy and spatial demands contribute to its classification as the most dangerous among turnabout maneuvers.