Update: the mod author has officially abandoned the mod, if you wish to take over the mod, pm the author via the forums.

• New in 0.4.1:
  • updated to .16
  • fix for crash on startup for 16.3+

Mod Info:
This is a small mod that adds a multi-tile structure that replicates the behavior of n-belt splitters. The mod adds a new method of item distribution from a splitter- called 'priority'- that favors maximizing output on one belt, before trying to output to the next belt in line. This splitter expects only one type of item on the belt and ignores belt side when picking up and placing items on a belt.

I made this mod to help me increase UPS on my larger bases and to hopefully take advantage of the power switch that will be added in version 0.13. Mod's with a power switch exist that might help with UPS but I'm waiting for the in-game implementation. This mod does not perform better versus n^2 type splitters with a width smaller than 8 belts.

How To make one:

• Place the cs: lane pieces to the width of the bus
• Place a cs: buffer piece to one side of the splitter.
• Place the belts for the input and output belts. input belts face the middle lane pieces, and output belts face away from the same lane pieces.
• Add the programming 'totems' to control the input and output mode. one for input lanes, and one for output lanes. they should be placed adjacent to the buffer or the end-cap (the last piece placed). priority in/output is given to the belts closet to the priority totem for that side. The gfycat above shows two of the valid totem placements (a full round robin on the right, and a priority output on the left).
• Add the end cap to the end opposite the buffer chest. You should get a message saying a splitter has been made correctly or a diagnostic message that should help you figure things out.

Action Shots:
An 8-belt priority splitter

Full Change Log:

• 0.4.1:
  • fix for crash on startup for 16.3+
• 0.4.0
  • updated to .16
  • minor updates to performance
  • removed modded transport belt. belts are migrated to the vanilla express belt (the equivalent).
• 0.3.5
  • fix for removing buffer chest on an active splitter
• 0.3.4
  • added migration script to fix known issue in 0.3.3
  • the script data is rebuilt by searching for all endcaps and attempting to run the detection script
    as if the endcap had just been placed.
  • the force of the buffer piece is pushed to the entities that were migrated from "simple-entity" to
    "simple-entity-with-force"
  • messages relating to a splitter during placement of the endcap relay to the player creating it
  • fixed group-icon/technology-icon image dimensions
• 0.3.3
  • removed on-demand event registration for multiplayer compatibility
  • all splitter pieces are now blueprintable. endcap must still be placed last
  • known issue: only pieces placed after 0.3.3 are blueprintable
• 0.3.2
  • fixed multiplayer join issue
• 0.3.0/0.3.1
  • Ported to 0.15
  • Technology requires high tech science pack instead of alien science packs