Final answer:
A double solid line on a road indicates no passing is allowed from either side due to safety concerns such as oncoming traffic.
Step-by-step explanation:
A double solid line in the center of a two-way road means that vehicles on both sides of the line are not allowed to cross it. This usually indicates that it is not safe to pass other vehicles due to oncoming traffic or other visibility issues. You are expected to stay on your side of the road and follow the path without overtaking vehicles in front of you.