They have reasonably fixed it now, with high level mobs being mostly in high level mini-zone. No more Gobbu, Peiste, Morbol, Redhorn Ogre, Boar etc. on the road anymore, so stick with the road, it's usually safe.

Like I said, a little warning toward the high level mini-zone would do a lot good. Ever played FO:NV? Right at the start of the game, you can choose a very deadly shortcut heading North toward Vegas instead of the long back-track route following the story-line toward South. NPCs around the road to the North would actively tell you how dangerous it is. It's great, it's immersive, it's reasonable and it's actually challenging should you choose to brave the dangerous short cut (I did).