Hardly you can get a better idea of what a deadlock is than looking at this picture:
(from The daily WTF)
Incidentally this appears to be not just a real life deadlock, but also the results of software bug as most of the deadlocks I’m faced with turn out to be.
I also guess that most of the drivers and passengers involved in the jam would have heartedly approved that extra bit of testing, or that extra money required to hire an experienced professional that would have prevented a deadlock-avoiding device such as a traffic light transformed itself in the deadlock-causing device.
Talking about problem-solving, how would you recover from this situation?