Here's the thing: a glass is either full or not full. An egg carton is full or not full. A freeway, on the other hand, can be "nearly full", "full," "overfull" or "packed to a standstill" and it never reaches the same "full" state as a glass or an egg carton.
Ethereum transactions more accurately mimic the freeway than the egg carton. It's not like the buffer overruns and the transaction fails out forever; it sits there until it goes.
EDIT: no wait. That's the beer talking. It does fail out. But there's still a "congestion" period where it doesn't fail out and that should be explained, in my opinion.
Maaan. Should not drink a 22oz kirin on an empty stomach.