What do two solid yellow lines on a road signify?

Two solid yellow lines on a road are a clear indication that no passing is allowed in either direction. This road marking is used to enhance safety by preventing overtaking in areas where visibility may be limited or where it may be hazardous for vehicles to switch lanes. It’s crucial for drivers to adhere to this marking to reduce the risk of collisions and ensure the safety of all road users.

In contrast, the other options do not reflect the meaning of two solid yellow lines. For example, allowing passing in either direction could lead to dangerous situations where vehicles attempt to overtake other cars without a safe clearing. Similarly, markings related to school zones or pedestrian safe zones involve different configurations and aren't indicated by solid yellow lines. Therefore, understanding that two solid yellow lines mean no passing is vital for safe driving practices.