In the Suez Canal Problem, we consider the real-world, multimillion dollar question of traffic flow through the Suez Canal. The Suez Canal is 193 kilometers long, 300-365 meters wide, and 21 meters deep.
The number of ships desiring passage through the canal is essentially the same in both directions in each 24-hour period. The region of the canal available for ship travel is approximately 169 meters in width.
This is not enough to allow simultaneous travel in both directions. As a result, the ships must travel in convoys either North-South or South-North.