![openttd priority merge openttd priority merge](https://wiki.openttd.org/uploads/en/Community/Junctionary/Dual%20Transmog%20Junction%202.png)
Outgoing tracks or exit are the reduced amount of tracks which leave the merger. Or entrance, also substituted with incoming tracks and similar terms, are tracks which go to the merger. Is the option given to trains to choose from the output tracks in a way that no matter from which input tracks do trains come, the input will not jam until all output tracks are full. Is a specific case of merging where one direction gets priority, can also be called SLH-style merge.
![openttd priority merge openttd priority merge](https://image.slidesharecdn.com/gettinggitright-full-140315020557-phpapp01/95/getting-git-right-149-638.jpg)
Is the general name for the mess where tracks X output as tracks Y. It is important to call things not just with an unified name, but also with a name which intuitively signifies what are we talking about. Whenever trains come from multiple tracks and are meant to exit in multiple tracks, they need to be able to choose their exit in order to make all exiting tracks used effectively. Just slight changes or even expansions at some other hub will most likely mean that trains will come on different lines and in different ratios. One of the problems is that you cannot even expect the traffic correctly in the long term. With perfect randomness, trains will indeed go like that, but in a normal game they will not. The important thing to note is that the percentages are not entirely wrong, but they are first of all only theoretically expected traffic, and second – average theoretically expected traffic. The logic for people who do not know about proper Merging yet is theory that line A will have about 50% traffic going this way while line C will also have about 50%, therefore logically they give 100% in line 1, and the same applies for B + D = 2.
![openttd priority merge openttd priority merge](https://www.evozon.com/wp-content/uploads/2019/08/5.-Setting-an-IAM-policy-to-an-existing-instance-800x469.png)