If the center lane is marked by a _____ _____ _____ line on both sides, drivers traveling in either direction may use the center lane for passing.?

The correct answer is a single broken yellow line. This line configuration indicates that the lane is a shared center lane, which is designed for use by vehicles in both directions for passing or making left turns. The single broken yellow line signifies that drivers may enter this lane from either direction, as long as it is safe to do so. This allows for more flexibility in traffic flow, especially in areas where turning or passing might otherwise create congestion or hazards.

Other line markings convey different meanings. For instance, a double solid yellow line would indicate that passing is not allowed in either direction. A single solid white line is typically used to denote the edge of a lane or to discourage lane changes near intersections. Double broken white lines may indicate lanes that are meant for specific turning movements but do not allow the same passing flexibility offered by a single broken yellow line. Understanding these markings is crucial for safe and legal driving practices.