Let's just say that on my visit to LA last year, I drove around through Labor Day traffic, as well as weekday rush hour traffic on the major highways - and couldn't understand why everyone was staying in their lanes! I kept looking over my shoulder for cops or cameras, or something! I mean, everyone complains how terrible driving around LA is, but it seemed tame to me - besides the heavy traffic.
For the DC beltway (and MD beltway, and Rt 95, etc) you'll want to install some ramming bars on the *sides* of your vehicle. Lanes are suggestions, not rules. And changing from one to another seems to require no predetermination. Speed limits are enforced by police, every so often. Otherwise it's every man for themselves - and get out of my way!
Oh - try not to make eye contact with people on the beltway unless you get a good look at them first...
Also, people on cell phones have the right of way.
And if an auto accident is even somewhat visible from the road you're driving on, you're required to come to a complete stop to gawk, even if the accident is on the other side of the road, or on a side road, or just involves a car getting pulled over, or changing a flat tire. Under no circumstances should you actually stop to *help* someone - you're job is to just gawk at them.
I'm sure I missed a bunch of "rules" that I consider so basic they're not worth mentioning!
'68 Firebird, 350-4, 2 spd auto, triple black, Dlx Interior