You have to take a holistic approach to the zone, treat it as a living thing. Kind of like a bear - you don't mess with it, or poke around in its territory, and it won't give you over much grief.
Traveling about with a convoy, collecting every convenience and treasure to be had, will make you a target for bandits. Going along with just a hatchet and your wits - what can they steal - where's the profit? Never mind getting all that stuff probably involved stepping on some toes. The rival recovery team? The village you nearly bankrupted for payment? Maybe some military guys who don't want you picking over their old vehicles and the bones of their comrades?
Don't forget about the reanimates. The more you poke about in urban areas, the more of them you see. Now I can't confirm this, but I just have this strangest feeling that they can remember you. Reanimates know the trouble makers from the good boys. Dumb as any type one is, we've seen them show group intelligence before. They attack in mixed groups with threes commanding attention so Betas can get close, type ones trigger the mine field so that others can get through, even if that trap stops the whole bunch, somehow the creatures know to use a different approach next time. And damn, for creatures that can't speak, they certainly know how to organize a group.
I suppose you're going to wait for me to say "the journey of a thousand miles begins with but a single step" and go on about the preparations you need for any sort of travel. Well screw that, its all a bunch of BS. The more you try to prepare, and the more stuff you pack, the more fuel it takes to move it, the more spares you need to bring to ensure nothing gets left behind if the vehicle breaks down, the more batteries you need - run as fast as you can to stay in one place. As a hippy would say - "you don't own stuff, stuff owns you".
Well, that works for me anyway, though I am a live off the land explorer. Your results may vary, void where prohibited, and see box for further details.
What to expect then? Well remember - if its a hot tip - it isn't. Someone passed that information along, and most things are either known, or lost for a damn good reason. If no one has raided that factory, it may well be because a tailings pond burst its dams and the air is toxic. Otherwise, someone probably has been there already. Not that you won't find anything, but look less for treasure, and more for investment opportunities.
You may face bandits, the type you meet depends - the bold or the well armed take to the often traveled roads, in spite of caravan defenses, the more desperate hunt off the beaten path. Other adventures, possible, but more likely to find reanimates wandering aimlessly. The Citizens do occasionally explore new areas just for the knowledge, but more often than not, if you meet them, they have a mission.
Wild animals can be a problem and a big one. Those stories about tigers in Illinois? Not really stories. You have plenty of animals that got out of zoos either from their own ingenuity or keepers trying to be more merciful than leaving them to starve in their cages. They feed on the carcases of just about anything - especially those stupid toy breeds of dogs - and are used to humans. Kind of a bad trait in a 300 pound predator. Feral domestic dogs are also not afraid of humans either, so watch out for them too.
Don't get me wrong, its still a great place to travel, and most days you'll be alone with your thoughts and the concrete bones of the modern age. Its that one day in twenty where you run across a mutant walking corpse, an alien war-machine, opportunistic bandits, Southerners on a mission from god, and an emu that test your skills.