This is something I've noticed since the Detail Texture option was added to the game.
Other places, everyone I've talked to has said it's because it's using up all my v-ram and on and on. Which, isn't true. Monitoring my v-ram's usage shows that it doesn't change with the option enabled or disabled.

But, with the Detail Texture option enabled, in the first Wasteland... whenever I leave a location like Wellsprings, or Mutant Bash TV... it takes roughly 30 seconds to fully load everything in and run smoothly. If I try to move around, it only makes it take longer. But after this first 30 seconds or so, the game runs great. Solid 60 frames.
Now, I thought this was due to the size of the Wasteland and me moving from smaller locations to the larger one...
But, upon starting a new game, I find I can leave the Ark... and it runs silky smooth. I can continue playing, do the jobs for Dan... the Outriggers... and drive around the entire wasteland without issue.
But, once I enter the a smaller location that requires a loading point from then on there's the pause.

But it's only in the first Wasteland.
Other locations like Dead City work fine. And the Eastern Wasteland... runs great. No issues. With the Eastern Wasteland I don't have to wait 20 to 30 seconds before moving about.

And with the monitoring software up, I can see that when leaving Wellsprings to enter the Wasteland it says my frame rate is at 60, video memory never changes. Card and CPU are not overheating.

Is there an issue inherent to the first Wasteland and the Detail Texture option?