When is it legal to cross a solid white line?

• A. You should not cross a solid white line except to enter a highway from the shoulder or to avoid a hazard when allowed.
• B. You may cross for any reason.
• C. You may cross if you are turning left.
• D. You may cross to pass another vehicle.

Answer: (A)

The rule is that a solid white line is a boundary you generally should not cross. It marks where lane changes are discouraged or where you’re leaving the travel lane, and it helps keep traffic moving safely.

You may cross a solid white line only in two situations: to enter a highway from the shoulder, or to avoid a hazard when it’s allowed. In either case you must judge the safety first—check for gaps in traffic, signal, and make the maneuver only if it won’t create a danger to yourself or others. Crossing to pass another vehicle or to turn left across a solid line isn’t allowed, and you shouldn’t cross for any other routine reason.