Cairo is one #($%&$#'n crowded city!!! horns constantly honking, traffic jams around the clock.. it's crazy! just check the fotage!
officially Cairo ranks in the top 25 most populated cities (according to wiki it's #22 with 6 million people). with the trains and commuters, this number doubles. i've never been in a place so crowded!
think New York, then make the buildings right next to each other and take away all the parks and add more buildings... triple the traffic and take away all the traffic laws.. sprinkle in a few donkeys and you're beginning to see the picture.