To help prevent car sickness while reading, use the “make sure the horizon is in view” approach by back-illuminating the page you’re reading with a pattern that remains, from an inertial perspective, stable.
A notepad holder/device cover (like iPad) with a low res led pattern, a gyro, and an accelerometer. The led matrix would display a pattern that would remain relatively constant in space, held by the gyro and accelerometers.
So, as you bounced your way down the rail line, the page would appear to move around on the pattern, matching the acceleration signals from your semicircular canals.
With a decent graphics card, this could be built into laptops/tablets to move images, text, or the whole screen image, around on the display space.
Fixed patterns would also make an interesting Halloween costume.