Which lane marking indicates that crossing is prohibited?

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The lane marking that indicates crossing is prohibited is a solid yellow line. Solid yellow lines are used to delineate traffic lanes and signify that vehicles must not cross over into the opposing lane, typically found on roads without a physical barrier separating traffic in opposite directions. This marking enhances safety by preventing dangerous maneuvers that could lead to head-on collisions.

The other choices do not effectively communicate the same prohibition. Double white lines, for example, indicate that lane changes are discouraged but not necessarily prohibited. A yellow dashed line allows for crossing, making it clear that passing is permitted. Dotted lane markings generally indicate a merge area or transitions, where vehicles can move in and out of lanes legally. Thus, a solid yellow line clearly establishes that crossing over into the opposite lane is not allowed for safety reasons.