Personally, I would not recommend you wear contact lenses on a roller coaster for the sake of your eyes. As we know, when we play roller coaster, there are strong wind that may accelerate evaporation of the moist of your eyes. So, If you playing roller coaster too long, it may dry your contact lenses in eyes that hurt your eyes. Nevertheless, there some some people wear them on roller coasters and still be OK. So, it depends on you.
When playing the roller coaster, the speed is so fast. Wearing both the eyeglasses and contact lenses are not suggested. When the speed is so fast, the airflow coming into the eyes may stimulate the eyes. If you wear the contact lenses, the eyes may get the infection. What's more, the contact lenses are easily fallen out because of the fast airflow. Thus, you'd better not wear contact lenses when playing roller coaster.
You must have bad experience when you in strong wind. When you are wearing contact lenses, your eyes are easy to become dry. Once wind blows though your eyes, the wind will get away the surface liquid and your eyes will feel very dry. When you are on roller coaster, the wind is very strong, your eyes will feel very ill and more serious situation is that your contact lenses will fall off from your eyes. Therefore, I recommend you to take off your contact lenses before you get on roller coaster. Or you can wear special glasses for protection.