When are yellow lines typically used on a highway?

Yellow lines on a highway are primarily used to separate two-way traffic lanes. This designation is crucial for safety, as it allows drivers to clearly see the division between vehicles traveling in opposite directions. When you encounter a solid yellow line, it indicates that passing is not allowed due to the risk involved in crossing into oncoming traffic. In contrast, a broken yellow line signifies that passing is permitted only when it is safe to do so.

The other options relate to different uses of road markings. For instance, one-way lanes are typically indicated by white lines. Crosswalks are usually marked with white or yellow paint and are designed to direct pedestrian movement. Speed limits are displayed on signage rather than through line markings. Thus, the use of yellow lines specifically addresses the separation and management of traffic flow for vehicles traveling in opposite directions.