Many of the airports I’ve covered in this ongoing series on former hubs have had to figure out how to shrink down to a smaller size to match the lower demand for the airport once the hub disappeared. Nashville has not had that problem, and it just keeps growing and growing.
Nashville’s original terminal was on the west side of the field. This was a tiny terminal that was built in 1961. It was quickly overwhelmed, and so plans were created about a decade later or so to build a new terminal further to the east on the other side of the runways.

This terminal was under development for years, but it didn’t actually break ground until 1984. The need became obvious one year later when American announced it would open up a hub in Nashville as part of its plan to better blanket the country.
Once the new terminal opened in 1987, American’s nascent hub grew fast. The airline took over all of the C gates, the end of B, and it used D as its regional concourse.

The hub peaked in the early 1990s, and then American shifted course. It abandoned the Nashville hub in 1995 and, as is almost always the case, Southwest moved in to backfill.
As I mentioned earlier, other hubs have often had to downsize, but this wasn’t that big of a hub in the first place — about half the size of Delta’s Cincinnati hub — and the growth from Southwest came fast and furious. Instead of trying to figure out how to shrink, Nashville had to figure out how to grow even further.
The airport made a few early changes, creating a bigger headhouse and a single security checkpoint to better accommodate local traffic needs (versus a conneting hub). That got Nashville into the mid-2010s, but then it was time to make more significant investments as demand continued upwards.
First up was the BNA Vision plan which rebuilt and lengthened the D concourse and added a satellite concourse parallel to the C gates. That was followed by the New Horizon plan which further extended the D gates (in red below) which opened last July and then prepared to rebuild the A gates entirely (also in red).

That new A concourse will open in 2028, but until then it’s a bit of a jumble. Here’s the lay of the land today:

Delta and United use the B gates and all the cats and dogs use the C satellite. American uses part of its old hub concourse on C, though it’s down to only seven gates. Southwest has all of D alongside the rest of C. Remember, Southwest shifted its mains Southeast hub from Atlanta to Nashville in the last couple of years, so the airline is clearly hungry for more space.
How this all shifts when a new concourse opens remains to be seen, but I’d imagine it would make a lot of sense to push American to the new A gates and give Southwest control of C.
You might think this growth would be enough to keep Nashville in good shape for awhile, but the airport has grand plans. It already has designed a new Terminal 2 further to the south, across runway 13/31 which would be an enormous change when built out.

This isn’t expected to be ready until the late 2030s, if then, but there’s a whole lot of time for plans to change between now and then anyway. With Southwest seemingly quite pleased with the shift of focus from Atlanta to Nashville, that airline’s growth may very well determine when (or if) that new Terminal 2 is needed. But the chances of Nashville needing to shrink back down like other former hubs? That’s just about zero.
