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

A solid double yellow line in the center of the road indicates that no passing is allowed in either direction. This marking is used to enhance safety on roads where passing could create dangerous conditions, such as on curves or near intersections where visibility is limited. The solid line serves as a clear warning to drivers that overtaking other vehicles is prohibited, thereby reducing the risk of head-on collisions and ensuring the smooth flow of traffic.

The other choices relate to conditions that are not represented by a solid double yellow line. For instance, a bike lane would typically be indicated by specific road markings or signage, and a pedestrian zone would be marked distinctly to highlight that it is an area for pedestrian traffic only. Likewise, markings indicating permitted passing would involve dashed lines, which are not applicable in the context of a solid double yellow line.