As you can see, I set up a waiting area for trains to stop (if needed). so Let's just say I have 4 trains headed for my iron Drop off points. 2 trains for Iron Drop off 1, and 2 trains for Iron Drop off 2. If Iron drop off 1 and 2 already have a parked train there unloading, then my other 2 trains will stay in the waiting the area. However, if there wasn't anything at each station drop off points, the waiting area will allow a train to just "WIZZ" by without stopping at all.
I have tested this several times, however, Input would be appreciated.. Maybe I missed something?
Edit** I'm probably going to add Cross rails to the main rail lines after the waiting area.
![Image](https://forums.factorio.com/images/ext/5af430b919293222f8619f5c9c10a849.jpg)