In what situation should a driver double-check their surroundings before changing lanes?

Double-checking surroundings before changing lanes is crucial for safe driving, regardless of the traffic conditions or the presence of other vehicles. Situational awareness is a key component of defensive driving, and this practice helps drivers identify potential hazards, including blind spots, cyclists, pedestrians, and vehicles that may be approaching quickly from behind or in adjacent lanes.

Maintaining a habit of always checking mirrors and blind spots ensures that drivers develop a consistent routine that enhances overall road safety. This vigilance reduces the risk of accidents and increases the driver's ability to respond effectively to unexpected situations, such as a suddenly changing road or the actions of other road users. Thus, the emphasis on the necessity of always being aware makes it essential for optimal driving practice.