The gate has the ‘C’ designation because it is in Terminal 2′s C Concourse. The part of the terminal that is still under construction will be the ‘D’ Concourse. I haven’t been inside lately, but presumably Terminal 1 will be (or has already been) divided into the ‘A’ concourse south of the main entry, and ‘B’ Concourse North of the main entry, which is actually similar to the original designations. When the the Big blue Building (Previously Terminal ‘A’) was built it was supposed to be a temporary structure until the old terminal built in the 50′s was renovated or replaced. When the old main terminal (where the SW gates are) was renovated back in the 80′s it was briefly designated as Terminal B until the link was built between Big Blue Terminal A and the old building. After they were linked people thought it was confusing to have 2 terminals in the same building so RDU dropped the terminal ‘B’ designation. This of course led to some confusion over why there was a terminal A and C but no B. Anyway there you have it. RDU the Blue building ‘Terminal 1′ and the newbuilding ‘Terminal 2′ to alleviate this confusion and to bring the whole airport into compliance with international naming standards. I think you can find most of this at http://www.rdu.com.

Thanks for the explanation, Michael. I can understand that the international agreement is to number terminals, letter concourses branching from the terminals, and number the gates. With the completed Terminal 2, however, the gates will still be on one long, confluent hallway
http://www.rdu.com/terminal2/project/suppfiles/images/rendering-aerial.jpg
I can understand two concourses that come together as a “V” being designated with differing letters. However, it makes no sense to designate one end of a hallway differently than the other. Atlanta isn’t designating gates to the North end of the escalators differently than the South end of the concourse. “Terminal 1″ here has no distinct break in its concourse(s), so there isn’t any logic in breaking that confluent hallway into two distinctions, either.

Non-stop flights to Milwaukee, Gate C-24. Is this an April Fool’s joke?

Didn’t say I agreed with it, just explaining the ‘logic’ since you seemed confused. It’s kind of like the Inner/Outer Beltline ridiculousness. Let’s make it more complicated so we seem like a bigger city.

I have written part of the Wikipedia article on RDU, so I’m familiar with the history of gate labeling. I agree that there is no reason to have separate C and D concourses at Terminal 2, given that the concourse is just one long hallway. Sure, departing passengers leaving security will walk into middle of the hallway — but that’s how Atlanta is, too. Going forward, it would be simpler if Terminal 1 had just one concourse (“A”) and Terminal 2 had just one concourse (“B”).

But, it appears that when T1 is modified for a new security screening area upstairs, it will have Concourse A to the left and Concourse B to the right — with T2 having Concourses C and D.