Those aren’t mountains.
These are mountains. 
A key question is going to be “How much American History is too much?” Alabama/Mississippi may have all the Civil Rights history we could want, but will that be of the slightest interest to Aussie males, especially youngish ones?
Re: New Orleans – thirded. Relax and spend enough time there to get to know its funkier, less Dinsey sides.
This all sounds very expensive.
Depends on who you are and how you travel. Travel can be relatively cheap or expensive. Out West, we tend to camp a ton. Bring a little dome and a sleeping bag and you can get a spot for 15-20 bucks a night. If you really want to be cheap, you can ask locals for free spots, but no bathroom, so… In the east, it’s harder, but you can frequently priceline for 75 or so in an ok hotel. The cities and tourist areas are more expensive, but you can still find deals if you’re slumming it. For food, grocery stores, coolers and camp stoves are your friends. You can go cheap on sites and souvenirs.
I would say minimum for a family of four is 600 a week. A moderate amount to spend without too much deprivation is about 2000 a week.
Even your definition of “cheap” is too much for me. When I travel, I sleep in the car/camper hiding in the trees off the highway. Pay to camp? Pfft!
“Fugitive” =/= “Traveler”
It’s a Fair Cop…
CruiseAmerica can set you up with an RV fairly cheaply if you want to be able to stop and see places where there aren’t any motels.
If I didn’t have any monetary limit, I’d rent one in LA, drive it to Jacksonville, fly to Key West and back, then rent a regular car for the East Coast run and over to say Minneapolis. Then rent another RV for the run across the Square Empty States to Seattle and down the West Coast. Drop it off in San Francisco (just call it “Frisco” like the locals do) and finish the trip back to LA in a regular car.
Neither of the boys drive as yet. So I’d likely be on my Todd Malone.
I’m unsure about RVs given I haven’t driven one or a car with a trailer and there are enough driving differences as it is.
Distance driving isn’t a problem, at least in the local context. The rest of my family all live are a bit under 1,000 kms away and when driving there SOP is a 10 hour trip with one stop across “don’t even bother stopping for gas” stretches.
The expectation is that we’ll be starting with a well maintained vehicle but cars do break down. What are the options to get service if necessary and avoid a couple of marooned Aussies (and prohibitive expense) ?
Just throwing this out there:
IF you can rent a car from one of the big guys for a trip of that distance/time and if the car breaks down, they will send someone to swap it out. Or, at least they did when it happened to me 10 or so years ago.
Ah - I didn’t notice that you were from Australia - so yeah, add an RV into the mix of driving on the “wrong” side of the road, and it’s a recipe for stressful driving.
If you’re sticking to main(ish) roads, you’ll never be that far from help. Obvious make sure you’ve got a decent cell phone. Some remote parts of the west may not have the greatest signal - when we were out in Arizona etc. in 2010, there were places where my cell phone’s nav application couldn’t get a signal at all. But unless you’re on really, really rural roads at really, really off times of the way, someone will be along.
It might be a while, though - so if you see a sign like “last gas for 40 miles” or some such, make sure your car’s tank is at least half full. I made the mistake of telling my husband “Oh, we’re fine” just as we passed such a sign… and THEN looking at the fuel gauge. We made it to the next town - barely. It was summer, in the desert, too. Fortunately it was night-time so we wouldn’t have cooked alive, but it was a foolish thing to do. Speaking of which, always make sure you have water and snacks when travelling in the more remote areas.
The one place where we were at all worried if something had happened was when we were leaving Zion NP to return to Kanab. The “more direct” route was undergoing major construction and the trip to the park had been difficult, so we left via a different entrance that was an hour longer. Unfortunately, by then it was quite dark, and we saw no other cars on the road. We were fine - but you don’t see roads that empty anywhere near where we live!
The rental company will certainly make good if the car fails. In the more remote areas, of course, it might take a while - and I don’t know how it would work if they had no office nearby.
Do make sure to reserve a car with unlimited mileage. That’s quite common nowadays, though I recently found when renting in a small town in Vermont, that anything larger than a sedan did NOT come with unlimited miles (renting the same larger car here at home still does). And, get a larger vehicle - an SUV or even a minivan. You can do the trip in a sedan (we did it in a Mazda 626, about the size of a Honda Accord) but especially with 3 of you, and 4-6 weeks’ worth of luggage, you’ll appreciate the extra legroom.
Consider getting the extra insurance that covers anything you might do to the car. For most Americans, it’s a scam - most of what it covers is already handled under your own auto insurance, but for someone from outside the country, it would reduce the headaches. Sadly, it is spendy - 15 bucks US a day is not uncommon.
Time of year: You won’t want to do it in the wintertime. Some of the highways in the midwest and west can get shut down in a bad snowstorm - even the interstate highways. If you do travel that time of year, make plans to stop if it looks dodgy. Snow is NOT to be underestimated, especially if you’ve never driven in it - and ice is even worse. High summer would be miserable in the southern parts, though air conditioning helps a lot. When we travelled through Las Vegas in July 2010, it was 115+ F (45ish C) - but the car’s air conditioner made it pretty tolerable when we were actually driving.
You could do a hybrid trip - part train, part car. The downside there is that you’d pay more for the car as you’d be dropping it off in a different city.
Good parts to skip over (i.e. take the train instead of driving): pretty much all of the east coast between Jacksonville, FL and New York City. Well, there are certainly places to see en route (e.g. Washington, DC; Baltimore MD has a rather nice aquarium etc.) but nothing unmissable. Ditto from New York to Chicago. I can’t speak for much of the southern route - probably nothing unmissable between New Orleans and Jacksonville but I haven’t been that way, so don’t take my word for it.
You really don’t want to have a car in New York City: if you’re driving, you go to the hotel the first day, have them valet-park it, and leave it until you’re ready to leave town. I’ve spent a lot of time in Manhattan and the transit is so much, much easier (assuming you don’t have luggage) than driving.
I wonder if that varies by office.
We usually rent from Enterprise and have always gotten unlimited mileage.
Though, we’re travelling periodically to a small town in Vermont, and when we get there (via train) and need a car, anything SUV-sized or larger has limited miles; anything smaller has unlimited. The same vehicle rented here (Virginia) was unlimited regardless of size, and we drove one to Canada last year - not “bordering” at all.
I don’t recall whether you were considering crossing into Canada at all. You’ll want to verify that your car can be taken across the border in that case (was not a problem for us last year). Mexico is a different story.
Thank you for the voice of experience;
Am a bit more used to seeing signs like this. 
Looking back through the thread, about the only bit where there isn’t some dissenting voice of experience to skip is the LA to the Grand Canyon leg and the Pacific West Coast!
This will take quite some time to nut out, but I’m certainly not discouraged from the venture.
I love the “camel / wombat / kangaroo crossing” sign. In many parts of the US, you’ll see “deer crossing” signs; in parts of the far northest (e.g. Maine, and when we visited Quebec last summer) you’ll see moose crossing signs. All the driving we’ve done up there in the past few years, and yet to see a single moose. I keep wanting ti complain to the signmakers for false advertising. Near Chincoteague, Virginia, some wag pasted bright red stickers at the ends of the noses of the deer on the “deer crossing” signs :D.
600+ km with no fuel, though - wow. I don’t think there’s any place in CONUS (Continental US) that would be that long between fuel stops. Possibly along the AlCan highway (drive through western Canada to Alaska) or the Dalton Highway (Alaska to the Prudhoe Bay drilling areas) - but those aren’t CONUS of course. I guess you have to bring along a few extra cans of fuel when doing such a drive.
The most startling signs I’ve ever seen in the US are these. They were along highways in southern California - around San Diego and a bit north.
I’m quite excited on your behalf. It’ll be truly a lifetime worth of memories - ours was certainly that, 33 years ago now.
If you do decide to drive the whole thing, and want to consider saving money, you could hit a camping supply store and get some basics once you land. A few hundred dollars should get you a basic tent, bedding, some cooking supplies, and a lantern. If you’re concentrating on “natural wonders” for your trip (as opposed to, say, “cities” or “tourist attractions”) it’s a fantastic way to get into the middle of things, and can be considerably cheaper than hotels. Some of the National Parks have both campsites and hotel accommodations; camping might be easier to find there (the hotels typically book up quickly at the popular ones like the Grand Canyon). Depending on where you’re landing, some local Doper might even be able to lend some supplies.
Speaking of moose (and other wildlife): We saw moose in Grand Teton, both on a hike (across a lake; a cow and a calf, I think) and in our campsite where a large bull moose walked right on through, ignoring us. Bison both in Teton and Yellowstone. Wild goats / sheep in both places as well. I don’t recall seeing bison or moose in Glacier.
Never saw a bear, though on one hike in Glacier we found that they do excrete in the woods… well, on a walking path. The staff there asks that people report bear sightings so they can keep track of where the bears are hanging out, and figure out whether there’s any danger. We popped into a ranger station to report the “steaming pile” we’d seen that day, and apparently they have a special form specifically for scat sightings, LOL. We wore bear bells (strings of jingly bells that make noise as you walk); the ranger said her colleagues dismissed those as useless - but she wore them and never encountered a bear, while they HAD seen bears. As I’m quite sure that had we seen a bear, it would not have been the only thing shitting on the path, I was just as glad we were spared any closeups.
Do get travel medical insurance before coming here. US medical care is (in)famously expensive, and your funds could get wiped out by an accident or illness. I don’t know if Australia has any coverage for your care when travelling overseas - but you might not be able to count on it paying up front.
This reminds me: do make sure to get paper maps as well as relying on your cell phone for navigation. If you’re in an area with a spotty cell signal, and don’t have a dedicated GPS unit (which I expect works regardless of the cell system), it can be really helpful. As recently as 2014, we had trouble getting sufficient signal to navigate in northern Vermont.
Most states have “Welcome Centers” when driving into them along the interstate highways, and often on major US highways as well. You can pick up free maps there, as well as hints on directions and tourist attractions.
And speaking of “interstate” versus “US” highways: Numbered highways in the United States - Wikipedia
“Interstate” refers to 4+ lane, limited access highways. US highways predate them; they are often just 2 lanes, though they can be 4+ in places; they are usually “at grade” i.e. with intersections, though in places might be limited access (requiring ramps to enter / exit). They’re more pervasive - lots of places with no interstate have a good US highway serving them. They’re well-maintained, and a lot more scenic / interesting than an interstate, though you won’t get to your destination as fast.
Bumping: Is the OP still considering this trip?
The OP is planning the trip.
Several ducks, including the participants, need to be lined up.
It’s not imminent but fully intend to go.
Any update? Planning on this year or next? I keep thinking “better get moving, summer is here!” then I realized that as you’re from Down Under, travelling during “summer break” would be a very different time of year for you. If you’re travelling during Australian summer, that puts you here potentially during heavy winter. In the “coastal” areas (well, east of the Mississippi, west of the Rockies and Sierra Nevadas), that shouldn’t be a huge hindrance; snow happens, but typically won’t be too awful - at most, a day delay if you’re sticking to major roads. Here on the east coast, we do sometimes get snow before Christmas but it’s usually not a big deal. I can’t speak to how challenging a mountain crossing would be that time of year but you really would need to allow for the possibility of hunkering down a couple of days if there’s a bad snowstorm over the mountains.
Do not underestimate the hazards of driving in snow: you’re most likely not familiar with it, and a rental car will not be equipped to drive in heavy snow as I found out last winter: I had an all-wheel-drive SUV in Vermont, and there was a snowstorm. Small potatoes by local standards, and I grew up driving in snow, but it did NOT have sufficient traction (permanent residents there all have snow tires or chains).
If you do a train for part of it: We just took a train trip from the Washington, DC area to Chicago. We got sleeper accommodations (a roomette). That’s cramped for 2 people; with 3 you’d need 2 roomettes. Put the kids in one, and you in the other. The Bedroom sleeps 2 and is more comfy but is also a lot more expensive.
You might get by with a Family Bedroom depending on the size of the 2 younger ones; teenage or above, someone would be very cramped (the secondary bunks there are not large enough for anyone remotely adult sized).
Well folks, or at least those who gave a toss last time all of three years ago in the pre-COVID world, the Grand Tour is back into the serious planning stage.
Time has advanced and it is probable this will now be just the cantankerous antipodean on his lonesome but I guess there will be less arguments in the car.
Planning time is mid-May to mid-July. Take about 7 weeks.
The 1st draft of the route is below: Approx 15,000km or a bit over 9,000 in your measures. POIs and stops are only indicative.
Nowt of this is set in stone and is all subject to whim/persuasion.
I haven’t convinced my-self to bypass New England … maybe one of the locals could sell me a pitch. Everybody I have talked to assures me that Glacier is mandatory but maybe not in high summer.
What other things should I do and/or avoid? All suggestions considered on merits.
Plan is to drive the circuit, but if a train fits the schedule, that’s something to monder.
Kind Regards
PT
Nothing but encouragement from me. May I suggest a book to take along? Steinbeck’s Travels With Charley, an account of his “lap of America” back in the early 60s. His vehicle (Rocinante) is in the Steinbeck museum in Salinas CA.
Hope the trip is great!
