What is the farthest you have ever driven without seeing another car? I would say about 50 miles. I once had to work very late on a holiday in a town 50 miles away from me. Nothing like having the interstate to your self the whole way home from work!
Probably from Peach Springs AZ to Hualapai Hilltop Hwy, above Supai in the Grand Canyon, probably also around 50 miles. It was 5 am in the morning, just the prime to for folks to start their downward hikes in the summertime, but I guess they were all going at the same speed I was, and people had already started their upward journey, but hadn’t arrived at the opposite-direction going road yet.
I also don’t remember seeing another car on the road between Raton AZ and Amarillo TX which is a greater distance, but I am not 100% on that, and I did run into an active road crew whose stopped vehicle may have counted.
I also don’t remember if I saw anyone driving at 3 am in the morning between Taos NM and Alamosa CO, which was 60 something miles, but I was confident enough to stop and relieve myself even though it was in the middle of a featureless plain.
Middle of the night on I-70 in western Kansas. Not only didn’t I see any other cars, for a long stretch I couldn’t even pick up anything on the radio. Loneliest time I’ve ever driven, even with my wife and kids there.
The “UFO Highway” across Utah and Nevada, after midnight. I had it completely to myself for maybe forty miles. It was great.
(Midnight, full moon, going through “Skull Rock Pass,” with old Lone Ranger episodes on a distant radio station. Greatest driving experience of my entire life.)
One time, right in the heart of San Diego, at about two in the morning, the 805 freeway was deserted. I was the only car in sight. I came to a complete stop. Cool. Totally stopped on an empty freeway.
Then…I turned around and drove the wrong way on the freeway, for maybe a 1/4 mile. Then, way off, I saw headlights, so I swung around again and drove properly.
(That was decades and decades ago. It would never happen today. The 805 is busy absolutely 24 hours a day.)
I think maybe a minute, maybe five minutes that one time I drove through Montana.
Probably 10 miles tops at 3AM on the Taconic Parkway in New York.
A couple of months ago I was driving home from town. I was on 58 in Missouri, and I went about 15 miles without seeing another car. At 8pm. That day, I had read a thread here in which a couple of posters said they had several red boxes within a mile of their homes, and that blew me away. I thought it would similarly be weird to those city folks to drive 15 miles at 8pm and see nothing but cows.
I left Elko Nevada late one night and took highway 51 (now 225 in Nevada) north through Duck Valley Indian reservation. It’s 140 miles from Elko to Bruneau, Idaho, and I saw three cars, so somewhere in there I must have gone a long long ways between cars. I drove that route often from 1978 to 1981, and it is one lonely stretch of highway.
Driving from Cheyenne, WY and Rapid City, SD in the 1980s I decided to take “the scenic route.” There was a 45 minute stretch, probably 40 to 50 miles, during which I didn’t see another car.
I did that a few years ago really early in the morning (spent the night at the little lake on the reservation) and I don’t think I saw a single car… until the state trooper pulled me over for 80 in a 70 about 20 miles north of Elko. I still to this day wonder if he just sat there and gave every single driver one of those $25 “rural speed” tickets.
In the US: going across montana late at night in the 80’s. probably two hours before i saw headlights.That was on the interstate some probably 120 miles or so.
In Tibet: at least half a day. That was probably more like 50-60 miles but through desolate yet beautiful big fucking mountains on a single lane dirt track
I live in Southern California so like… 200 feet? Tops. 
US Highway 6 “Grand Army of the Republic Highway” thru central Nevada - about 50-60 miles during daylight, mid 90’s weekday. That’s some lonely road out there.
About 100 miles - from Ely to Tonopah NV on Highway 6. Also about 100 miles on a dirt/sand road somewhere near Soleb, Sudan.
I just drove “the Loneliest Road in America” for a good distance last weekend (US 50 in Nevada). What a crock of shit - there were quite a few people. I’ve driven longer without seeing people (the time of day might’ve been a factor, for example 395 through Southern California at night I didn’t see anyone going my direction for hours), while I’ve driven stretches that made me more uncomfortable that I haven’t seen a gas station in over an hour (such as being close to E in an unfamiliar car on CA-89 through Lassen).
Mine was another drive mostly in Nevada, from Bishop to Beatty, a driving distance of about 150 miles. Of that distance, the first fifteen or so miles are heading south on US-395, and that’s a fairly well traveled road. I probably encountered other traffic up to that point. But once I turned east towards the Nevada border the roads got very lonely indeed.
I enjoyed it hugely, what with all that empty space – mostly ranches–from one horizon to the other. I passed by several ghost towns and stopped to look at the ruins of one of them, not that there were many to look at. To be frank, I don’t care to live permanently in that type of environment, but it’s certainly nice to visit.
I saw hardly any houses as a matter of fact. I assume that there were ranches because there were cattle crossings on the highway. But I never saw the houses where the ranchers and cattle herders lived; they must have been miles away from the highways. IIRC, Nevadan ranches tend to be huge in acreage because of the arid climate; it takes acres to support one cow, or something like that.
I was expecting to see some Australian Dopers in this thread.
Surely somebody from Down Under can out-do the Yanks on this. 
Australia? Certainly.
In the interim I can say that Asian visitors to New Zealand find the empty reaches of the South Island frightening. The Mackenzie Country and the Maniototo. Empty lands.
High speed nirvana for a motorcyclist like myself but strange places.
That’s a fascinating thread.
I’ve lived all my life in Belgium, one of the most densly populated countries in Europe and there simply is no such thing as completly desert areas. Unless you’re in a forest, you can always see some lights - a small village, a few houses - somewhere in the distance, even in the most “remote” places. The only way I can sort of make sense of the idea is by remembering my stay in Canada back when I was 14. It was in Southern Ontario so definitely not isolated but I did have that feeling of being in a huge, huge place: going to school one Monday morning after spending the weekend near Lake Erie. A mere two-hour drive for my host family. A mind-boggling, alien experience for me.
Reading your stories makes me feel strangely serene, as if I was living them by proxy.