I've driven through the western desert portion of the US several times. Even on "well trafficked" roads, you might not see another car for half the day. I've also driven through rural portions of Oklahoma, Texas, Colorado, and New Mexico where I've seen plenty of traffic, but not much in the way of towns.
When I drove to Ft. Bliss one summer to be with my daughter-in-law while she had surgery after returning from Iraq, I drove through the panhandle of Texas, then through the corner of New Mexico, and back into Texas. And made the return trip the same way.
I thought I was prepared for that trip.
Turns out, not so much. I made it, but only by the kindness of strangers and the Border Patrol. That kind of freaked me out - I was nowhere near the border when I happened across a Border Station. I would have understood it while I was in EL Paso - the border was right there.
Here's what I learned:
Gas stations, when you can find them are often closed and don't always have pay-at-the-pump options so you can still pump gas when they are closed. Top your tank at every opportunity. And have at least 5 gallons of gas in a gas can for those times when you run out of gas before the next accessible station.
I never quite ran out of gas, but I came might close on the return trip home. A gas station I'd stopped at on the way out was not just closed but out of business (yes, that quick), and I'd relied on it being there for my return home. I did not expect it to close up shop forever between my trip out and my return trip 4 days later. Fortunately, someone who lived locally drove by and stopped to help. She advised me to drive really slow - 25 miles an hour tops - and she'd follow me. If I did run out of gas, she'd then drive me and the dogs to the nearest station (about 45 miles away) to buy a gas container and gas and we'd find someone to drive me and the dogs back to my car.
I coasted the last 50 feet into the station on fumes. I'd started at the remote gas station with just barely a gallon of gas left in my tank (foolishly expecting that closed up station to be there).
Lesson learned - top your tank at every opportunity.
Also - make sure your car is in tip top condition, All your fluid levels are topped off, Your anti-freeze/coolant is in good shape, you have spare water for the radiator and spare fluids for other parts of the car, your tires are in good condition and your spare is a full sized spare not those nasty little temporary donut tires. Make sure you even have a spare tire. Newer cars are being sold without a spare. Their reasoning is that most people have a roadside service insurance that will come out and fix their flat for them. I don't know what world they live in, but it's not mine. Full sized spare tire. You'll need it in desert driving.
I didn't have a cell phone, but my daughters do. One travels a lot, and has traveled through deserts with her cell phone. She says don't rely on it. In the deserts and remote rural areas, there are no relay towers and therefore no service. Satellite phones should work, but even they might not be reliable.
CB radios generally do work. When I was younger and had all my hearing, we'd travel a lot and we relied on CB radios.
GPS is not always current, accurate, safe, or even provides accessible routes. It doesn't tell you about road closings, washed out roads, roads covered with rock slides or mud slides, or other hazards. Don't rely just on your GPS for travel planning. That's probably a good idea for any kind of travel. Sync the GPS up with recent maps of the area and call for road closings. Some states and cities list their road closings online, you might want to check those. But even then, they might still not be accurate. Have back up routes and plans in place in case you need to back track and use a different route.
There are lots of road hazards in the desert, some are man made. the roads, for example. Speed limits are often insanely fast, the roads are often narrow and lack dividing lines, and the pavement quality varies greatly. Drivers will be either driving insanely fast or insanely slow so be prepared to squeeze over for the speedy ones and resign yourself to creeping behind the slow ones until you feel safe enough to pass them.
Don't hesitate to drive slower than the posted limits - those speeds are for the locals who are familiar with the roads and any hazards it may have. They know when the pavement changes what times of year they're likely to encounter wildlife and flash floods and such, so they'll drive accordingly. You may not know all that and more. Locals won't mind if you drive slower as long as move over when they come up behind you. I've had plenty of them smile and wave at me, giving me a thumbs-up because I'm obviously not local and I moved over for them.
If you're not hearing impaired, you can tune your radio to the local weather station or news station - they will broadcast warnings about the weather conditions: wildfires, flash floods, high winds, sudden rain storms, mud slides, rock slides. If you're hearing impaired, stop often and ask the locals. They'll tell you. Well, they told me, anyway. I'm sure they'll tell you.
Spring and fall are usually the best times to drive in the desert. Summer can be brutally hot, can overwhelm your car's A/C. Travel between late evening and early morning when possible and hole up somewhere shady during the hot part of the day. Winter can be deadly for a different reason - it gets surprisingly cold in the desert in winter. Dry and very cold. It still looks like a hot desert, what with all the glaring sunlight and miles of sand and cactus and desert brush. But it's fooling you. Even in the summer, the nights can get beyond brisk and chilly and down to frigid.
A tan top and shorts may be nice when bopping around the city or close in rural areas, and maybe even when comfortable when driving, but be sure to pack desert appropriate clothes in case you break down. The last thing you want to do when you break down in the desert is expose your delicate skin to the very hot, very dry weather. It will suck the fluids right out of you, and give you the sunburn from hell. Pack sunblock clothing (you can use treat natural fiber clothes with Rit Sun Guard to make your clothes be a better layer of protection for you), or at least long sleeved shirts and long pants and a sun hat. Don't forget sensible shoes - ones that protect your feet from the blistering sand and pavement.
If you're traveling with pets, make sure they have foot protection, too - that sand can get very hot and blister their tootsies. They make summer sandals for pets. It doesn't take long to train your pet to wear them, even cats can learn. When the alternative is burning hot sands or pavement, they learn surprisingly quickly (or ice, snow, mud...).
If you do break down out in the desert, stay with your car. You'll be much more visible and easier to find.
When driving in the desert, you should stock your car with lots of extra water, a tent and sleeping bag (in case you get stranded for more than a few hours), extra food, a good ice chest with ice in it and nothing else - it will stay frozen longer and you can dip into it for ice for your drinks or to cool yourself off, a flare gun so if you get stranded after dark, you can shoot a flare every now and then to mark your location for potential rescuers, the means to cook some food, a first aid kit (a good one, not the cheapie little ones from the dollar store), a pocket knife, and a snake bite kit. Scorpions, snakes, and spiders are a real hazard when you are stranded by the road and camping out in the tent waiting for help. A comprehensive tool kit is a plus, too. If you have an awning you can erect using one side of the car to support it, and some comfy folding chairs and books or games, that's a plus.
If you have pets with you, a harness and extra long leash and a pet first aid kit and cooling mats for them to lie on (an ice chest of their own, filled with frozen ice blankets is good. Refreeze the blankets at hotels - most will do it for free, some have a small fee - they'll freeze the ice chest, too. Refresh your ice chest.
The hard part is if you break down in the desert will be keeping your pets cool. Shade, lots of water - iced for as long as the ice lasts, the ice blankets for as long as they last, and those cooling mats and body wraps help, especially if you can fan the dog or there's some breeze.
Remember, your cell phone may not work, so you're reliant upon other drivers to report your location or to stop and help you.
I'd recommend some means of protection if you're traveling alone or with small dogs. Not everyone will be willing to help you so you need something you can use to protect yourself. The car is a good - you can lock yourself in it. The problem there is that it gets really hot really fast even if you were lucky enough to find shade. Someone with ill intent could simply wait you out and watch you and your pets die of heat stroke. I don't often recommend having a gun, and it might not be legal, but this is one instance where I'd suggest having a gun or some other means of self-protection. When I drove the deserts, I didn't carry any guns. I had a really sharp ax and a really sharp machete between the driver's seat and the door that I could pull up at a second's notice.
For some reason, people are really scared of a demented old woman with an ax, much more so than a woman with a rifle. I thank Lizzie Borden's legend.
If you're traveling in iffy conditions in a less-than-reliable vehicle, let people know your itinerary and your estimated times of arrival, and regular check-in times and points. Even if your vehicle is in optimal shape, let them know anyway - things can happen. I've seen accidents where people get hypnotized by the miles and miles of endless road and desert and they run right into giant boulders or cactus, and in some of the desert mountains, those switch back curves are frighteningly dangerous.
Unlike road-tripping in most of the US, desert travel can present you with a variety of conditions that can be challenging. Pre-planning, lots of preparations, packing the right survival gear, and keeping someone informed of your travel plans and times are essential.
The desert can be a truly beautiful place, and it's a good place to get away from it all, as long as you know you can get back when you're ready.