In order to define the best vehicle these inputs have to be taken into account:
- The zombies are the classical ones, "the walking dead" ones are a perfect example (definitely killed only by headshot, attracted by noise, etc...).
- We are in year 2018. Population: 2% alive, 18% definitely dead, 80% zombie.
- The vehicle-proposing person must convince a party of 8-10 people.
- The party is heterogeneous, one or two people are capable to perform some minor mechanical/electrical intervention on a vehicle, for instance they can add metal spikes, fuel tanks, firing loopholes, etc. They can't change the engine with a more powerful one or replace wheels with tracks.
- Other specific, yet not really special skills, could be taken into account, for instance: one person could be really good at cutting and sewing, whether to use it to create nice curtains or a vehicle ghillie suit is up to your answer.
- The party could also use other vehicles for scouting or scavenging, like a motorbike and/or a pick-up, but the main vehicle must be able to carry safely the whole party (but maybe not comfortably, it's not necessary to have one seat per person).
- The party should travel to at least 5-6 different cities, 400 km far from each other on average, then they should find a final generic safe place. (400 km considering detours and menace escapes, see below)
- In the party there's a very intelligent person (which should also be the one proposing the vehicle strategy and path), therefore feel free to suggest nice tricks, but he's a regular guy without specific high level skills. For example: he could find a clever way to enter a building, but he can't pilot a bomber or hack a bank's safety vault.
- The party has some limited supply, and a relatively safe place for 7 days, therefore they have some time to organize the travel. They also have an initial mobility range of 20 km to find the final vehicle, and the 7 days can/should be spent also to modify the vehicle.
- They live near a center-Europe big town, 30-50K people, even if most part of the city supplies have already been scavenged by other groups, it is possible to find fuel, food and tools with some research. The research is time expensive, therefore if the vehicle is easy to find and it doesn't need modifications they can use the 7 days supplies to start the travel immediately with some stock. Even though I prefer to have a customized vehicle.
- I'd rather choose an European city instead of a North American one, because I don't like to have a lot of fire weapons involved in this travel. Of course hunting rifles and some pistols could be considered common weapons, but heavy machineguns are incredibly rare and RPGs/grenades are out of the discussion.
- The vehicle should therefore withstand some low caliber shots, but it doesn't need to be a military armored vehicle.
- Is also difficult to obtain any military grade gear because military bases are some of the most infested zone (emergency sirens attracted the zombies - they were the first choice shelter, but they eventually collapsed) or they have been reclaimed by huge groups of raiders.
- The party should expect (obviously) zombies, blocked roads (mostly because of abandoned cars), and raider scouts attacks (3-4 people, armed but without big guns). Because of the surrounding zombies and the raiders' reinforcements, having to repair the vehicle for more than 1h have to be considered as game over.
- The vehicle's speed is not really important except for the fact that a slower vehicle must carry more essential goods, and the faster ones are preferable because of flee chances. It is also valid the concept that a slower vehicle, yet capable to overcome most road obstacles, is actually a "faster" one with respect to a supercar that needs to take several dozens kilometers detours.
- Flying could be theoretically considered, but it seems to be really difficult to find the right fuel, the noise will attract a lot of unwanted attentions from both live people and undead, once departed there are no chances to go back (noise->zombie), the destination airfield could be impracticable, and especially there are no trained pilots in the party (this limit could be bypassed, but the other cons must remain and therefore it's hard to justify a flying vehicle).
- Railways could be an answer, but proper trains can't: every train except for few really old ones have electrical engines, and the diesel ones are not easy to be used by a common untrained person. Moreover, since at least any station is likely to have some trains on the nearby railway, the vehicle must be at least capable of both road/railway or to remove the blocking trains (also derailing the wagons and make them overturn could be an acceptable choice, but it's a long and noisy process).
EDIT, info from the comments: - The food is rarer than the fuel. The party, considering some distractions (zombies and raiders), can gather 30-40 litres per day using 4-5 people. The food is rarer, the most canned food is already consumed and the people now need to hunt, gather edible vegetables or fish. There's no overall lack of food, the wildlife somehow grew in large numbers when humans stopped their activities, the issue is to collect that food. Hunting is time expensive and food preservation is limited. Moreover the "food" is usually outside the cities, while fuel and gears are way more common in the cities.
Please describe a vehicle that fulfill the inputs, its most useful modifications, what to carry as essential goods and emergency supply and especially detail the reasons. If you think you have the perfect vehicle, even in case some conditions are bypassed, please still answer. Obviously the more conditions are removed, the less the answer will be interesting.
Bonus: Travelling on water can't be an answer to reach the safe place (it's far from the sea), but detours on water are appreciated to reduce risks and let the party rest a little. Let's say that a couple of cities are near the sea, therefore if the vehicle could be easily carried by a small vessel it would be better. For instance, a small van has way more chance to be carried than a "Mad Max style" war wagon.
Malus: I'm NOT ASKING for a zombie killer vehicle: even if it could kill several zombies, its main purpose is to carry 10 people for a long range trip. If you think that is safer and faster just to kill everyone in the path (zombies and raiders) by driving a huge beast on the vehicle then you have to justify it.
Edit: my question is related to this one What kind of land transportation can be used for plowing through hordes of zombies? because we are talking about zombie apocalypse, but it's a totally different approach: i highlighted as malus a zombie-smasher veichle. Even though is admitted to propose a zombie-killer vehicle, the main goal is to move the party safely through EU, not to destroy a Z horde.