What does a solid white line on the road indicate?

A solid white line on the road serves as a marker that indicates no lane changes or crossing are permitted. This line is typically used to reinforce the notion of keeping vehicles within their designated lanes, ensuring the safety and smooth flow of traffic. It is commonly found between lanes of traffic traveling in the same direction, such as on highways, and is meant to discourage weaving and unsafe maneuvers that could increase the risk of collisions. The presence of this solid white line helps drivers understand that maintaining their lane is essential for vehicular safety, contrasting with broken white lines, which do permit lane changes when safe to do so.