I had to think back to the last time I really felt disoriented by heights and it was about 20 or so years ago driving to Colorado. Texas is mostly flat so any mountains seem impressive.
And I'd driven through the Colorado mountains before, including Wolf Creek Pass during a blizzard in the 1980s -- that was a bit nerve wracking, but not for the heights issue. With the snow I couldn't see far anyway. It was just a test of nerves keeping the car on the road. I was delivering a nice used Mercedes to a dealer and this was the first I'd driven that didn't handle well on slick roads. Turned out later the previous owner had put the wrong size tires on the rims, and they were squirming around like crazy.
But my last trip through the Colorado mountains in the 1990s was the only time I felt disoriented ascending while driving. It's the visual conflicts going on -- the nearby mountains were like walls, and gave the illusion of "moving" differently from the more distant mountains and sky. I'm sure most folks get accustomed to it quickly. By the time we drove back home a week later it was less disorienting.