When is it especially important to check your blind spots?

Checking your blind spots is particularly critical before changing lanes and merging because these actions require an awareness of vehicles or objects that may not be visible in your mirrors. Blind spots are areas around your vehicle that are not visible through standard mirrors, and other vehicles can occupy these spaces unexpectedly.

When you prepare to change lanes or merge, you need to ensure that the path is clear not just in your primary mirrors but also in these hidden spots. This precaution helps prevent accidents caused by not seeing nearby vehicles, which could be in the process of overtaking or may be positioned directly next to you.

By making a habit of checking your blind spots during lane changes and merges, you enhance the safety of yourself, your passengers, and others on the road. The other situations provided do not demand the same level of vigilance regarding blind spots. For instance, checking blind spots while driving straight or at a red light is generally less critical, as traffic is usually more predictable, and vehicles are in designated lanes. Therefore, the correct answer emphasizes the importance of awareness and safety during lane changes and merges, which are high-risk driving maneuvers.