What should you do before changing lanes?

Answer: A — Check mirrors and blind spots, and signal your intention

Before changing lanes, it is essential to check your mirrors and blind spots and signal your intention. This procedure ensures that you are fully aware of your surroundings, including the position of other vehicles that may not be visible in your mirrors. By signaling, you communicate your intentions to other drivers, which enhances safety and allows them to prepare for your maneuver. This protocol is crucial in preventing accidents and ensuring smooth traffic flow. In contrast, matching the speed of traffic is important, but it should not take precedence over the need to check mirrors and blind spots. Alerting other drivers by sounding the horn can create confusion or panic and is not a standard practice for lane changes. Lastly, speeding up unnecessarily risks losing control of your vehicle and can lead to dangerous situations. Hence, the correct and safest approach is to assess your surroundings by checking mirrors and blind spots before making a lane change while signaling your intention.