Final answer:
Two sets of solid, double, yellow lines spaced two or more feet apart serve as a traffic barrier to separate opposing lanes and prevent hazardous passing or lane changes.
Step-by-step explanation:
Two sets of solid, double, yellow lines that are two or more feet apart indicate a barrier. This means that crossing the lines is prohibited and that they serve as a division for opposing directions of traffic. This configuration is a safety feature on roads to prevent vehicles from dangerous passing or lane changes in areas where it would be hazardous to do so, such as on curves or near the crests of hills.