I'd disagree with most of your second paragraph there. I've seen that kind of behavior (in fact I did that when I was a lot younger) and it doesn't work. I've seen drivers that did that arrive at the ...

60,000 cars x 30 second gaps (ignoring car length) moving at 20 mph = 10,000 miles of traffic. 60,000 cars x 30 second gaps (ignoring car length) moving at 60 mph = 30,000 miles of traffic. Where does ...