Final answer:
Two solid yellow lines on a road mean that passing is not allowed from either direction. This marking is used to maintain road safety and prevent collisions, which is unlike the rules for other types of lines like dashed yellow or dashed white lines.
Step-by-step explanation:
Passing is not allowed in either direction on a road with specific pavement markings. When you see two solid yellow lines, it indicates that you cannot pass from either direction as overtaking other vehicles or changing lanes is prohibited to prevent collisions and maintain safety.
This is in contrast to other line patterns you mentioned, such as one dashed yellow line and one solid yellow line, where passing is allowed when the dashed line is on your side; a dashed yellow line where passing is typically allowed with caution; and a dashed white line, which usually differentiates lanes of traffic moving in the same direction, and crossing it is allowed when it's safe to do so.