WILLIAM, I see you have found your way over to flyertalk as well. Welcome!

Yes, ATL does reach nearly 1/2 way to Chattanooga along I-75. Which is part of the reason why Metro ATL's proposed route for the Maglev high-speed rail project would begin down around Hartsfield and end at the Chattanooga airport.

As there are no true boundaries to development of the area, suburbs have given way to exurbs. Soon the exurbs will be the new suburbs as new centers of population sprout farther and farther from the core of the city, in all directions, I might add. Metro ATL has the largest toll-free calling zone in the country, and I believe the world. That tells you how large the area is.

MARTA (rail) is only 20 years young. Actually, for only being in existence for two decades, they have done rather well expanding the system. Planning to extend the West line out to Six Flags over GA, and the North line has two new stations opening at the end of the year. And yes, I'm quite sure that the Metro in D.C. got a lot more support and $$$'s than MARTA to become the far reaching efficient system it is today.

Believe the parking decks at ATL will be expanded once more, by adding an additional level to each (as was done in the mid 90s). That would add about 4K more spaces.

How many spaces does an airport need? There are currently 31K of them at ATL. Guess as long as demand for travel continues to rise, so will the need for more parking.