Is it possible for the driver of the vehicle to get carsick?

I was just curious. I don't think it is, but last summer, my friend (who gets motion sick fairly easily) and I, along with others, went to an amusement park about 5 hours away (my friend drove). When we got there, he started looking for Dramamine because he said he was feeling a little sick. Could he have really been feeling motion sick from driving down there or was he just using that as an excuse to take some before the roller coasters?