What does a double yellow line in the center of the road indicate?

A double yellow line in the center of the road signifies that no passing is allowed in either direction. This marking is used to ensure the safety of all road users by preventing overtaking in areas where visibility is poor or where it may be inherently dangerous to drive on the opposite side of the road. The presence of double yellow lines indicates that both lanes of traffic must remain in their respective paths without crossing into the opposing lane, which is crucial in maintaining a safe driving environment.