[quote=Emuxe]
I think it should start before characters meet. Or during (early on, perhaps), so not all characters are by themselves to begin with, also so they're not all together. Characters and groups can run into each other and either join together or go their separate ways.Though how hard do you say it'll be to survive? Because I quite like zombie/apocalypse RPs where you have to try to survive - where food and supplies are scarce, and you can't even trust the water (needing to purify it via boiling and cooling before even using it). That would also force people to stick together to survive.
[/quote]
On a scale of 1-10 I would rate the difficulty of survival at around 7.5-8.

I would imagine that the water would still be, at the very least, consumable. Some sources of water would obviously be more hazardous than others though, and many will probably leave the characters with some short-term parasites/illnesses. Maybe even one or two long-term ones if our characters get unlucky. 

As for food we are going to have to scavenge up food when we get the chance, which won't be often early on. Also we are going to have to keep a constant supply of gas to make any progress, and of course ammo supplies will have to stay stocked to kill any significant amount of zombies, and I'm planning for the zombies to be very hard to kill so sticking together would be the best idea for actually making it through this alive. 

All in all we're in for one hell of an uphill climb. With a few twists of course. 

The very beginning will be a cakewalk until we get a mode of transportation though.