There is probably nowhere that the unofficial rules of the road are "enforced" by other drivers like that of the lane closure line up. You know, the long line up of traffic that forms on one side of the highway after drivers pass the lane closed ahead advisory signs. Drive by in the empty lane and I've seen people open their doors or swerve partially into that lane to let other drivers know that they are supposed to be in the line up, not using the capacity in the empty lane to get ahead.
The trouble is, this is not the best way to behave when traffic approaching the lane closure is heavier than what can be accommodated by a single lane. What everyone should do is be aware that the lane ends ahead, continue with caution using both lanes, and at the end merge like the teeth in a zipper before proceeding through the zone single file. This will move 15% more traffic than the situation where everyone moves over and lines up when they start to see the signs. If we're lucky, this method will only slow us down, but not cause us to wait in a line that is virtually stopped.
If traffic is light and no line has formed, merging early is perfectly acceptable. Due to the lower volume, a backup will not form to cause delay.
These practices are acceptable because the black on orange signs used in these situations are advisory. A driver can choose to take the advice (or not) as their experience, traffic and road conditions would dictate in the circumstances.
Flag persons, cones, barricades and the like are traffic control devices that must be obeyed. Once you reach them at the point where the lane is closed, it becomes an offence to fail to follow their requirements. Now you must move over as indicated, but not before.
http://www.drivesmartbc.ca/lanes/approaching-lane-closures