White lines separate lanes for which travel is in the same direction. A double white line indicates that lane changes are prohibited.

What do 2 white lines mean?

Double white lines are two solid white lines that indicate a lane barrier between a regular use and a preferential use lane, such as a carpool/HOV. Never change lanes while in these lanes; wait until a single broken white line appears. You may also see these parallel lines in or near freeway on and off ramps.

When can you cross a double white line UK?

Double white lines where the nearest line is solid

“You may cross the line if necessary, provided the road is clear, to pass a stationary vehicle, or overtake a pedal cycle, horse or road maintenance vehicle, if they are travelling at 10 mph (16 km/h) or less.”