A lot of people believe you must never cross a continuous centre line.
But that's not the rule.
You certainly can't overtake when there's a continuous centre line and you can't do a U-turn across one.
But you are allowed to cross a continuous centre line if you are entering a road or leaving a road.
Even if there's a broken line on the other side, you're still permitted to cross the continuous centre line if you are entering or leaving a road.
But remember, if there's a double continuous centre line, you're not permitted to cross it at all.
Similar rules apply to painted traffic islands. If the island's surrounded by one continuous line, you can drive on or over it for up to 50 metres in order to enter or leave the road, or to enter a turning lane that begins immediately after the island.
But if the island's surrounded by double continuous lines, or if it separates traffic flowing in the same direction, like where an onramp merges on to a motorway, you must stay off it, unless you need to avoid an obstruction.
Doing it the right way is easy when you know how.