A couple of thoughts while driving
The drive to see our grand-daughter entails going over the Altamont pass (yes that Altamont). It's not a tremendously high pass - just a tad over 1,000 feet - but for some reason traffic, all four lanes of it, slows by 5-15 mph. It's not like modern vehicles, at least most of them, can't hold a steady speed. Heck I do it in whatever I'm driving. It makes no sense and drives me nuts. At least pull over a lane or two if you slow down. Don't block every single lane. And then of course everyone is back to going 10 mph over the limit on the downhill run.
The other thing is people that drive 75-80 on the straight sections but have to slow down to 60 around the curves. On a multi-lane highway. This tells me one of two things about these drivers; a) either they are driving way too fast or, 2) they are incapable of going around a corner. Either way they should just stay off the road until they learn how to drive.