What does a single broken line on a two-lane road indicate?

A single broken line on a two-lane road indicates that traffic moving in opposite directions is separated by this line. This type of marking helps maintain a safe flow of vehicles by clearly delineating the lanes for oncoming traffic. It allows drivers to understand that while they are facing opposite direction vehicles, there is still the potential for overtaking vehicles within their respective lanes, as the broken line suggests that passing is permitted, provided it is safe to do so.

In contrast, options that mention merging, parking areas, or marking no-passing zones do not accurately describe the function of a single broken line. Merging pertains to situations involving lane changes, while parking areas typically do not involve markings that influence the flow of traffic on the road itself. A no-passing zone would be marked by a solid line instead, indicating that overtaking is not allowed in that section of the road.