NewBe, you seem hung up on saying it NEVER snows in the Atlanta-Dallas swath--and honest injun, it can and does and ties things up. Maybe it won't when this young lady goes--but it pays to stay tuned to the weather no matter what it may be.

And people are trying to be helpful, I think. I do think we need some more info--is she returning? What kind of budget does she have? Internet access (Ipad or smart phone) on route for making reservations, etc.

<NewBe, you seem hung up on saying it NEVER snows in the Atlanta-Dallas swath>

Not at all. I am saying that this statement:
<<And in December you are likely to find snow even in some normally warm areas.>>
is flat wrong.

Snow is not likely on this route in December. What's so hard to undestand about that?

Other statements on this thread were harsh and condescending. Were they meant to be? Only you know. But surely adults realize that tone matters, so if you're trying to be helpful, as you say you are, maybe watch that?

I'd be surprised if the OP returns, but I hope she does.

Snow is not likely on this route in December. What's so hard to undestand about that?

Not a thing, except it is YOU that are dead wrong. Take a look at the google page I posted. Goodness!! It can happen. Everyone is saying be aware of it.

As for the OP, I hope she returns also and gives more info.

But I am not dead wrong. Saying it could happen is not the same as saying it's "likely". It's not "likely".

Therefore, this statement:
<<And in December you are likely to find snow even in some normally warm areas.>>
is, to borrow a phrase, dead wrong.

Kate,
I neglected to offer one lodging option that may help you. Look at YMCA's along the way. Its not as common nowadays, but some offer overnight lodging. Also, many state parks offer cabins or campsites- so look at what's available along your route. Some allow car camping, some don't, but campsite rentals are usually very inexpensive and you should have a little more security at a state park than some other potential choices.
And even if you aren't a AAA member, you can find great ideas from the guidebooks. Some libraries have them, and it may be possible to get a "limited edition" version to look at on their website.
You can find lots of great trivia about different towns and little known sites to visit that are free, or nearly free.
When you get further West, you may want to pick up Route 66 for a bit, and there are many resources for travelling that road, or what's left of it, most of which include roadside attractions that are related to the heyday of travelling that road.
Safe travels to you....!

And there are hostels in some cities. Tom Fuller has mentioned them from time to time.

Thanks for the mention of hostels. The hostels of Hosteling International are generally better than the others.
Do you need your car in California or could you rent one there if you took the train?
My plan would be to take the Lake Shore Limited from NYP to Chicago in coach. Spend a night at the HI hostel (on Congress) and then spend some time in Chicago.
Take the Southwest Chief from Chicago to Albuquerque.
Spend a night in the Route 66 hostel (not HI).
Take the next Southwest Chief to Los Angeles (overnight).
Rent a car in Los Angeles to see what you want to see.
When you consider the cost of gas, vehicle costs and hotels the train is more attractive to me.
If you can tolerate sleeping in coach seats, you would have a night between New York and Chicago, a night between Chicago and Albuquerque and a night between ABQ and LAX arriving by 9AM.
The HI hostel in Chicago is the largest in the US.

How do you get from lower east coast to New York?

But the OP says they want a road trip - and are starting from somewhere in the south - not NY.

In any case I assume she's not coming back. Either doesn't like info or waiting for a notice she has responses.

OP has started a new thread but hasn't indicated that she has read any of the responses here.

Well, why would she?

This topic degenerated into a cat fight topped by a completely irrelevant railroad trip.

Fodor's at its absolute worst!

Wait a second--why is it a "catfight"?

Because women are the ones disagreeing?

Having reread the posts, my own included, I see vehemence but nothing that could be described as a "catfight". "Fodor's at its absolute worst"?

Hardly.