The first, of course, is money. Aside from the economic pinch, bad in Washington and worse in Atlanta, Georgia transportation funding is mostly in the form of traditional - some would say outmoded - "road taxes." These are the levies on fuel that can be spent only on road and bridge projects. So money for other forms of transportation has to come from elsewhere, which usually means nowhere.
The other is habit. We Southerners love our wheels, and the sense (or maybe illusion) of independence they give us. Most of us would rather be alone in a car, even stuck in standstill traffic, than sharing space with our fellow travelers on the swiftest and most comfortable express train.
So even if we somehow cleared the first hurdle and managed to come up with the money to dramatically expand Georgia's high-speed inter- and intrastate rail service, the question remains: Will enough Georgians use it often enough to make the investment worthwhile?
In other countries and in many parts of this one, especially urban areas, the question is moot: Mass-transit commuting and semi-long-distance train travel are routine. Is it possible Georgia's ever-growing gridlock, especially in and around ever-sprawling Atlanta, and high energy costs will make us rethink old habits?
We could get a clue a little more than a year from now: A referendum on the August 12 primary ballot asks Georgians to assess themselves a 1-cent sales tax that would draw federal matching funds for transportation needs other than roads, including high-speed rail.
Meanwhile, some in Washington want to cut federal funding for rail projects as a deficit-reduction measure. They are concerned not just about the federal expense, but also about the possibility of states having to absorb operating costs.
Georgia has already been stiffed on federal money this year, a fact that prompted some to suspect the Obama administration of political motive. Yet Texas got $15 million and North Carolina $4 million. Red State/Blue State politics are probably less an issue than Georgia's request for $23 million just to relocate a single existing Atlanta train station about a mile from its present site.
Old habits die hard, and that probably goes double for our transportation habits. But by now we have more than enough proof we can't pave our way out of gridlock. Sitting stalled in traffic, whether we're on a 10-mile commute to work or a 200-mile drive to another city, is a poor excuse for independence, and no kind of energy independence at all.