When changing lanes, what should you always check?

When changing lanes, it is essential to check your mirrors and blind spots to ensure a safe maneuver. Your mirrors provide a view of the traffic behind and to the sides of your vehicle, allowing you to gauge the distance and speed of other vehicles. However, mirrors can sometimes create blind spots—areas around your vehicle that you cannot see in your mirrors. This is why checking these blind spots by physically turning your head is crucial; it helps ensure that no vehicle is in your way before you initiate the lane change.

While it's also important to be aware of your speedometer, the speed of your vehicle does not directly impact your ability to safely change lanes when compared to the immediate surrounding traffic. Other drivers' signals can provide helpful information, but they are not always reliable indicators of their actions or intentions. Understanding the weather conditions can affect your driving as a whole, but it does not specifically pertain to the action of changing lanes unless it is impacting visibility or road conditions at that moment. Thus, the most important safety measure before changing lanes is to check your mirrors and blind spots.