State laws regarding rules of the road may differ however solid white lines typically have the same meaning nationwide.

As the Florida driver's handbook states white lane lines separate lanes of traffic moving in the same direction. Single white lines may also mark the right edge of the pavement.

A solid white line marks the edge of the roadway or separates lanes of traffic moving in the same direction. You may travel in the same direction on both sides of this line, but you should not cross the line unless you must do so to avoid a hazard. Double solid white lines indicate that changing lanes is not allowed.

The California handbook only notes that solid white lines mark traffic lanes going in the same direction, such as one-way streets.

Both Arizona and Virginia note that solid white lines designate turn lanes and discourage lane changes near intersections and at other locations where lane changes might be dangerous.

So to get an exact definition of how your state defines a solid white line and if a driver may cross over it, as in the situation you described, you can check with your state's Department of Motor Vehicles or a local law enforcement officer.

The state's "rules of the road" will be used as well as statements from the drivers for the insurance adjuster to determine who was at fault or the amount of fault each driver had in said accident.