Wow, this is a great insight, i have been thinking about why for years. I remember in England they were everywhere. The USA is lucky to be such a new country. I traveled over 70-100 hours by road in Europe, and less than 10 percent was on 4 lane highways.
I lived in England for three years, the explanation I got was they were safer because all traffic comes from one direction and were less likely to cause traffic jams like stoplights and stop signs.
Also -Putin Khuilo- I got a kick outta this on Wikipedia "a possible English translation: Putin is a dickhead", and here is a link to the song http://en.wikipedia.org/wiki/File:Putin_khuilo_(song).wav lalalalalala.... LMAO