A double solid white line indicates that:

A double solid white line indicates that crossing the line is prohibited. This marking is used to separate lanes of traffic moving in the same direction. It reinforces the idea that drivers should remain in their designated lane and not change from one lane to another in that area. This regulation helps maintain the flow of traffic and ensures the safety of all road users by minimizing the likelihood of lane changes that could lead to collisions. In scenarios where changes between lanes could disrupt traffic or when merging lanes is not allowed, the double solid white line serves as a clear visual cue for drivers to stay put.