What is the primary reason to check your mirrors and blind spots before changing lanes?

• A. It helps you anticipate traffic patterns for fuel efficiency.
• B. It ensures there are no vehicles in your path and prevents collisions.
• C. It allows you to drive faster safely.
• D. It is only necessary in heavy traffic.

Answer: (B)

Preventing collisions is the core idea here: before you change lanes, you need to make sure there’s no vehicle in the lane you’re moving into and no one in your blind spots. Mirrors help you watch what's behind and beside you, but blind spots aren’t visible in them, so a quick head check confirms there isn’t a car entering your path. This practice dramatically reduces the risk of side-swiping or cutting someone off. It’s not about fuel efficiency, speeding, or doing it only in heavy traffic—the safety benefit holds in any driving condition.