Auto-Refitting Issue

[shanoaice]

I have a situation as follows:

• Station A, produces wood
• Station B, produces livestock and grain
• Station C, receives wood, livestock and grain and produces goods
• Station D, produces wood, relays livestock and grain from B and goods from C, goods are intended to be transported away by vehicles

There are 2 trains running with the following command, what troubles me is the behavior of Train 1

1. A: Load and auto-refit (wood)
2. D: Load and auto-refit (as-needed)
3. C: Unload, then load and auto-refit (goods)
4. D: Unload all for relay (goods)

(Train 2 runs from B to D, relaying livestock and grain)

Due to vehicle efficiency issues, sometimes good builds up at station D. As I was using a NewGRF which provides an almost universal cargo wagon, it sometimes picks up all the goods remaining on station D, runs to C, and return the goods at D, causing efficiency loss. What can I do to prevent this from happeneing?

[odisseus]

Build a separate station for transferring goods, and make sure that all trains have a "Transfer and leave empty" order at that station.