Vehicles are devices that are designed or used to transport people or cargo from one point to another. Vehicles are variety of categories including cars, trucks, airplanes, trains etc.
They generally ran on electric engines, drawing power from on-board batteries or nuclear powered with a small reactor to the rear of the vehicle, but vehicles running on petrol also exist. The super mutant army is also said to have used some steam-powered trucks. There are numerous wrecked vehicles in the Fallout world, but functioning vehicles are now extremely rare.
The Resource Wars were fought mainly for resources, leading up to the climax of the Great War. The last resources remaining were probably depleted in the war itself. Without resources, many vehicles couldn't be driven anymore, though some managed to cannibalize and salvage their way through. After the war, a lot of human knowledge was lost. People forgot how to tend to the high tech pre-war vehicles with their complicated electrical, oil or nuclear motors. Most books were damaged beyond all legibility by the war and many computers were destroyed due to years of neglect, and with them the documentation for these pre-war vehicles was lost. This combined with the lack of large scale primary and secondary industry meant most vehicle production/repair was largely impossible.
This does not mean that there are no old vehicles that have been kept functional or that someone out in the wastes could not have invented and adapted their own vehicles, but such instances are extremely rare outside of technologically advanced groups. (i.e. groups that have overcome the struggle for basic survival and can put resources towards researching old/new technologies) The current theoretical ratio of working cars is 1 for every 200 people.
By the 2240's, the New California Republic had managed to create a mechanized vehicle division. That being said, most cars one could find in the wasteland would be simple farming vehicles, such as taxis, buses, tractors, snowplows, and the odd construction vehicle. Most in the New California region would be glad to get their hands on them or create an infrastructure that accommodates such transport methods.
By 2281, the NCR had managed to rebuild a small amount of the infrastructure around the New Vegas area, specifically in train usage, as well as expanding its militarized divisions, though its not unheard of for an average citizen to own a vehicle.
Behind the scenes
- Fallout Bible 0#Timeline repair: Second strike: "2060 Traffic on the streets of the world stops moving. Fuel becomes too precious to waste on automobiles, so alternatives are explored - electric and fusion cars begin to be manufactured, but factories can only make limited amounts. Pressure on fusion research increases."
- Fallout Bible 5: "6. About how many working or servicable cars are there at the time of FO2? Obviously there must be more then one, since the guy in new reno has a garage fully staffed, and most likely has a large supply of parts( im assuming that was what the warehouse building next to the garage was filled up with, you couldnt pick up anything off of them)
Probably not too many, but I don't know the exact number. The real problem isn't fuel, it's mostly tires and other degradable parts that have gone to the dogs in the past 100 years. For every two hundred or so people, there might be one working vehicle, and even "the local clunker" wouldn't be up to factory specs. NCR is rumored to have a mechanized vehicle division outside of its farming vehicles, but the number of vehicles in the division is unknown."
- Fallout Bible 6: "6. Last update, you said there were 1/200 cars/people ration in the NCR. If there were so many working cars in NCR, where were they?
They're there. It's game logic. You don't see them for the same reason NCR is only three maps, only has 1 councilor/senator, and only about 40-50 people in its city limits. That's why the Chop Shop in Reno exists, why the bum outside of NCR offers to watch a car for you before you show up in one, and a reason that NCR built a garage in Shady Sands.
So to explain "game logic" in this instance, there's nothing precious about building a car of your own if you can steal one – or if somebody else in town has one. Or in the words of one designer (me), "there's no good reason why a PC would want to undertake a fucking huge Fed Ex quest to rebuild one if they can jack one from the locals." The last part is especially true considering town-wide mass murder is possible in both Fallout 1 and 2.
And before you get the image of tanks and jeeps flying around everywhere with heavy machine guns mounted on the back, most of that junk is old tractors and crap like taxis, old buses, snowplows, and even old construction equipment. It's possible that mysterious old steam-truck mentioned in the bowels of the F1 data archive is still lumbering around somewhere. The caravan houses of the Hub, in particular, around the time in Fallout 2, have been looking to further its trade influence, and new vehicles (and types of transport, such as trains, boats, or barges) have been eagerly sought after for carrying large amounts of trade goods vast distances. Good ol' human greed will move mountains. Or at least rebuild things that can. Once they learn of the Enclave's presence in the North, they are likely to have huge bounties promised for Vertibird plans - or better, a working Vertibird."
- The Courier: "Where does the concrete come from?"
Ike: "Most of the limestone comes from Quarry Junction out west. The supply had stopped for awhile because of a Deathclaw problem. I heard some badass wastelander killed the Deathclaws, and deliveries of limestone have been coming in again. I don't think they've gotten the trains up and running yet, but most of the concrete plant workers have come back to town now. Good for business."
- see New California Republic Army#Mechanized division
- Billy Knight: "I bought my wife a little car here in New Vegas. An Omerta. It has a hood under the hood."
(Billy Knight's dialogue)