If you haven't read "One Second After", do that before you do anything else. As a matter of fact, go to the damn book store right now and buy it. I hate to read and I read it in one night. Couldn't put it down as a matter of fact. I recommend it to everybody now. Probably the most important book I've read in the last 2.5 years. Spoiler Alert, Thread about it here: http://www.ar-15.co/threads/34413-Th...M+R.+FORSTCHEN
That said, I've run some comm-out scenarios and it's chaotic. People don't cope well, everything is disorganized and normal tasks/comm takes much longer. Now imagine if you no comms and no cars. Now imagine if you had no comms, no cars, and no electricity. Go get the book.