What is the meaning of a dashed white line on a roadway?

• A. It marks a pedestrian crossing.
• B. It marks lanes; you may change lanes or pass when it is safe.
• C. It indicates a no-passing zone.
• D. It marks a shoulder area.

Answer: (B)

A dashed white line between lanes traveling in the same direction means you may change lanes or pass when it is safe to do so. It exists to indicate that lane changes are permitted, as long as you signal, check for clear space in the adjacent lane, and have a safe gap. This is different from solid lines, which prohibit or discourage changing lanes or passing. In other words, the dashed line signals allowed lane changes when you can do so safely, rather than marking pedestrian crossings, a shoulder, or a no-passing zone.