Which action is necessary prior to changing lanes?

Before changing lanes, it is essential to adjust your speed and steering to ensure a safe transition into the new lane. This action involves several important considerations. First, you need to make sure that you are moving at a speed that is compatible with the traffic in the lane you are entering, allowing for a smooth merge without causing disruption. Additionally, this action also requires you to position your vehicle correctly within your current lane, making it easier to steer safely into the new lane without veering into adjacent traffic.

Other actions listed, such as signaling after changing lanes or checking your phone for directions, do not directly address the immediate needs for a safe lane change. Signaling is important but should be done before changing lanes, and being distracted by checking your phone could lead to hazardous situations. The focus should always be on ensuring that the lane change is executed safely and in accordance with traffic conditions.