What indicates that it is safe to pass another vehicle on a two-lane road?

A broken yellow line indicates that it is safe to pass another vehicle on a two-lane road. This line allows for passing when it is clear and safe to do so. The broken yellow line signifies that traffic in either direction may pass if the roadway is free of oncoming traffic. However, it's essential for drivers to ensure that the road ahead is clear before making such a maneuver, as other factors such as visibility and road conditions may also affect safety.

In contrast, a solid yellow line signifies that passing is not permitted, as it indicates that it may be too dangerous to do so due to visibility issues or other factors. A double solid yellow line reinforces this restriction, indicating that neither direction of traffic is allowed to pass. Lastly, a dotted white line is typically used to separate lanes of traffic moving in the same direction, which does not relate directly to passing other vehicles on a two-lane road.