What is the most critical factor in compensating for blind spots to the sides?

Looking over the shoulder is the most critical factor in compensating for blind spots to the sides because it provides a direct line of sight that mirrors alone cannot offer. While mirrors are helpful for general awareness of surrounding traffic, they often do not capture every angle or object near the vehicle, particularly in blind spots. By turning your head and looking over your shoulder, you can identify vehicles, cyclists, or pedestrians that might not be visible in the mirrors.

This practice is essential, especially before changing lanes or merging, as it ensures that you have a complete understanding of the area surrounding your vehicle. Other methods, like adjusting seat position or using parking sensors, can enhance overall awareness and safety but do not replace the necessity of visually checking blind spots through direct observation.