Final answer:
The first step in leaving traffic on a roadway is signaling the intention to change lanes.
Step-by-step explanation:
The first step in leaving traffic on a roadway is signaling the intention to change lanes. This is important because it alerts other drivers of your intentions and allows them to adjust their driving accordingly. Checking the rearview mirror, looking over the shoulder for other vehicles, and moving into the appropriate lane are all important steps in the process, but signaling your intention is the crucial first step.