This riddle describes something that becomes full at a station and then gradually empties as you travel. The word “station” is the strongest clue: think of what drivers commonly stop to fill before continuing their journey.
Answer: A car’s gas tank (fuel tank).
You fill the tank at a gas station, and as the car travels mile after mile, the engine uses fuel and the tank becomes emptier. The clue works just as well for other fuel-powered vehicles, but a car’s fuel tank is the classic answer.
It is a simple riddle once you connect “station” with fuel rather than a train or bus station.
