IAH finished the inter-terminal train a while go for UA/CO and everyone else.

The IAH airport terminal-link train (inside-security) now links ALL terminals inside of A <5 minutes.

This includes UA/CO's mega-hub @ IAH to Latin/South America (every single farking destination you can imagine, you name it, if it's there it's connected to IAH EXCEPT for SCL which I believe is coming...).