The slow lane on I-15 between Baker and Primm is separated by a solid white line from the other two lanes of traffic and is clearly marked for trucks and slow traffic only. It's illegal to cross a solid white line in California.
what happens when a slow person is in the far left lane? then noone can pass?
It's illegal for the slowpoke to hog the left lane and illegal to pass him on the right. Neither offense has probably ever been enforced in the history of mankind. I hate laws like that...if it doesn't need to be enforced, it doesn't need to be a law - and if it does need to be a law, then it damn well needs to be enforced. Speed limits are the same way. Raise them to the maximum allowable speed, then enforce them strictly. We'd all be better off.
AFAIK its illegal to cross a solid (lane marking) line of any color. In the rare occasion that I am trying to pass a vehicle that is going slow in the left lane (I'm usually in the far right lane being passed) I will flash my lights first, and give them an opportunity to move over before I pass on the right. A good rule of thumb is to look to your right, if anyone is passing, or has passed you, then you need to move over at least one lane.
I've seen state troopers pull over fast and middle lane slow traffic, in Arizona and California. In each case, the troopers tailed the slowpoke, signaled right to indicate an intended pass, and when the road hog failed to respond, they turned on their red lights and pulled him over.
I know that in England, they take "undertaking" (like overtaking, but done in the wrong lane) very seriously. The first time I did it with an English friend in the car, he reacted as if I blew a stop sign at full speed.
BTW I believe in Vermont, a double-yellow line only signifies that they advise against passing there- but it is still legal to do so. That might have changed.
All of the climbing lanes I've seen on the east coast have just been a third lane (separated by a dashed line like the others) that shows up on the right at the bottom of a hill and merges back in at the top, accompanied by "slow traffic keep right" and/or "climbing lane" signs.
The only lanes I've seen with a solid separator have been bike, HOV and bus lanes.
I drove in the slow lane to keep my 39.5 mpg trip average with my SE-R. The irony is I did the same trip in November with my wife's AT Hyundai Elantra and got 41 mpg.
Here's a link to photos of I-15. The opening photo shows the solid-striped truck lane at Halloran Summit. Search for "Halloran Springs Road overpass" on the webpage, and click on the associated photo to see the signage.