Double line lane markings we all know (I hope) mean it's dangerous and hence illegal to cross, usually into oncoming traffic on the other side of the road approaching the crest of a hill, blind curves, etc.
Continuous Single lines are simply Do Not Cross, drive on or over them. Example = slip lanes, lane markers at intersections, etc.. I see these lines are completely ignored as they are driven over in all instances such as cutting into or out of queued traffic.
I've never heard of anyone even being questioned about the ignorance of this law in Australia.
They save me tyre wear!