According to the U.S. Department of Transportation, dotted yellow lines indicate areas on a road where drivers may pass other vehicles. The less-common broken yellow line along the side may indicate the edge of the driving lane.
A basic two-lane road commonly has cars moving in opposite directions separated by broken yellow lines. Motorists driving along a stretch of road with dotted yellow lines may pass cars directly in front of them, as long as the opposite lane is clear. Drivers also may make turns off the roadway. Solid single lines alert motorists that they should not pass other vehicles, and these lines might appear next to dotted ones. It is important to pay close attention to road lines because they can change from dotted to single suddenly.