If you drive regularly on single-lane roads you’ll eventually need to overtake a slower vehicle, but before you do check the road markings ahead of you. These frequently appear as variations on double white lines. You’ll need to note if the white line nearest to you is broken or solid, or if both are solid. If the double white line nearest to you is broken, Rule 128 of the Highway Code says you may cross these lines to overtake if it’s safe, and you can complete the manoeuvre before reaching a solid white line on your side. You may also see white direction arrows on the road indicating that you need to get back on to your side of the road. Should the nearest double white line to you be solid, Rule 129 of the Highway Code says you must not cross or straddle these lines unless it is safe and you need to enter adjoining premises or a side road. There is one exception, you may cross a solid white line to pass a stationary vehicle, or overtake a cyclist, horse or road maintenance vehicle, if they are travelling at 10mph or less. So, if you’re sat behind a tractor doing 15mph, overtaking it would be breaking the law. Where both double white lines are solid, you must never cross these or overtake as they occur where visibility is restricted and overtaking hazardous.