What does a solid yellow line signify?

A solid yellow line signifies that no passing is allowed. This marking typically indicates that the road ahead may be hazardous for overtaking vehicles due to factors such as limited visibility, curves, or other dangerous driving conditions. It serves as a warning to drivers that they must remain in their lane and should not attempt to overtake another vehicle. This is particularly important in maintaining safety on the road, as passing in these areas can lead to head-on collisions or other dangerous situations.

The other options relate to different road markings or signs that indicate other rules or conditions. For example, a dashed yellow line would suggest that passing is permitted when it's safe to do so. A bike lane would be indicated by a different type of marking, typically a solid white line or specific bike lane signage, and a roadwork zone would usually have distinct signage indicating active construction or detours.