A double solid white line means you must not cross the line.

• A. Center line
• B. Single solid white line
• C. Double solid white line
• D. Broken white line

Answer: (C)

Double solid white lines indicate a strict no-crossing zone. They’re used to separate lanes of traffic moving in the same direction when crossing would be unsafe or confusing. Because both sides are solid, you must not change lanes or pass another vehicle while you’re within or approaching these lines. Stay in your lane and only cross them when you’re turning onto or off of the road where crossing is permitted by the turn, not for passing.

For context, a single solid white line often marks a lane boundary where crossing is discouraged, and a broken white line allows crossing to pass when safe. A center line can be yellow or white depending on the road, but the double solid white line specifically means you must not cross.