[throwway120385]

I'm sure they've started all of this a few times over the past decade. The problem is in the US if you can't start and finish a project like that in less than 2 years then it's effectively dead in the water. The last time we "modernized" ATC was closer to the 90's than today, when there was still some general political will to make our government agencies modern instead of tearing them to pieces.

[nradov]

The FAA NextGen program has been running for literally decades. They have made some progress but there's a lot of work left to be done.

https://www.faa.gov/nextgen