What does it mean if you see a solid white line on the road?

A solid white line on the road indicates that drivers must stay in their lane and not change lanes. This marking is typically used to signify that lane changes are discouraged or not permitted. It is meant to enhance safety by preventing drivers from weaving in and out of lanes in situations where it may be dangerous to do so, such as near intersections, in narrow lanes, or in conditions with heavy traffic.

The rule associated with solid white lines helps maintain a consistent flow of traffic and decreases the likelihood of accidents. Understanding this road marking is crucial for safe driving. Other choices suggest actions that are either permissible or required, which contradicts the purpose of the solid white line. These alternatives imply that changing lanes is allowed or that speed adjustments should be made, neither of which accurately represents the directive given by a solid white line.