On the two lane sections of I-5, among other busy trucking routes, you can encounter miles long convoys of trucks in the right lane. If you religiously stick to staying to the right, you and a whole lot of other traffic will be weaving between the trucks and changing lanes every minute or so. So nobody who's going 10mph faster than the trucks does that. If you actually did that, you'll likely get boxed out trying to get back into the left lane as soon as you come up on another truck -- you'll have a brief period where you're going 75 in the right lane, then you have to slow down to 60 to deal with a truck, then you go back to overtaking at 75, then get back in the right lane... rinse and repeat. What happens instead is that the people enraged by this will use the gap on the right to go 100mph past everyone who just wants to cruise at a steady speed past all of the trucks.
Barely tangentially related, but I5 desperately needs to be widened to 3 lanes with a strict "No semi trucks in the left lane, for any reason" rule that is enforced with impounding trucks, the goods they're carrying, and loss of licensing for the drivers and the companies they work for. I'm not even against making it so that CHP, OHP...etc, are allow to use the proceeds from auctioning off the impounded trucks and goods to fund themselves.
I've wasted far too many hours of my life getting stuck behind a left-lane truck on that road, trying to overtake a column of trucks in the right lane while going up a 6% grade.
