Pick a lane. The car-pool lane, the "fast lane," the truck lane, the merge lane—this isn't your typical freeway. First of all, keep out of the two far right lanes, which buses and trucks are restricted to. To drive the speed limit, pick the middle lane; the fourth lane moves about 5 miles over the speed limit. Newbies should stay out of the far left lane. Speeds here range from 75 to 90 mph and you've got to deal with car-pool-lane mergers. And what about that car-pool lane—also known as the diamond lane? Use it if you have two or more people in your car and it's moving along at a good clip.
Signaling is a must. You might be able to get away with a quick lane-change in other cities, but don't try it in L.A. Drivers may try to merge into the same spot as you from three lanes away.
Get a freeway map. The small, laminated maps that just cover the jumble of freeways are indispensable if you merge onto the wrong freeway, get lost, or get stuck in traffic and want to find an alternative route. Nearly every gas station sells them; you can get a decent one for a few bucks. You can also find one on the inside back cover of this guide.
Don't pull over. Short of a real emergency, never, ever, pull over and stop on a freeway. So you took the wrong ramp and need to huddle with your map? Take the next exit and find a safe, well-lighted public space to stop your car and get your bearings.