Car sickness, sea sickness, train sickness, fun fair sickness are all forms of "motion sickness". I never get car sick when driving but suffer terribly as a rally navigator. I still get sea sick and I've been boating for years.
In the UK there are tablets called "Quells" and I find these work perfectly. I'm sure there is something similar in the US.
If in doubt get something like this first as motion sickness is one of the most unpleasant things to endure,