If there are double white lines along the centre of the road and the line nearest you is continuous, you mustn't cross or straddle the line, except in specific circumstances. These include to enter premises or a side road, or to pass a stationary vehicle. You may also overtake a bicycle, horse, or road maintenance vehicle, provided they're travelling at 10 mph or less. You mustn't park on such a road, but you may stop to pick up or set down passengers.