Linear infection maps are some of the most fun ways to play infection and I don’t see why 343i or Bungie has never caught on to their popularity yet. They are really good Custom Games and they definitely shroud be in Matchmaking due to how well made these maps are and how unique they are in terms of their game play.
Here is probably the most linear infection Map in Halo Reach called “5 Levels of Terror”
Here are a couple of Halo 4’s best Linear Maps
“The 3 Switches”
“Station 92”
BTW: If you don’t know what a Linear Infection map is, It is basicaly a Campaign like infection map where the Human survivors are forced along a set path Tward an eventual end-point, however there are typically multiple areas holdout. which halt progression until an either timed or activated map event allows for players to progress further. Zombies/Flood gain access to each area though a series of specific teleporters that spawn in as time progresses
Here is a Tutorial on how to make these maps in Halo: Reach
And here is one for Halo 4