There was recently a massive traffic jam on a 50-lane highway in China and the aerial footage is unbelievable. It happened on a road right outside Beijing, at a toll both/checkpoint where a massive multi-lane highway transitions into a road with only a few lanes. Everyone was returning to the city from vacation at the same time, and because of the volume of cars and the narrowing of the road, the world's worst bottleneck was formed. Those people better have had some podcasts handy, or they were otherwise stuck playing 9999999 bottles of beer on the wall.

Sources: Sploid/Gizmodo