Frontier have held a number of Q&A's with the coaster head club over the past few months on the official forums and have confirmed a number of things-
-in the last Dev Diary where multiple coaster cars where seen on Vekoma track this is just part of their development build, in the final game coasters will have their own track as in the real world.
-All rides are based on real world designs, and will inc some older classic style rides/coasters. If it isn't possible in the real world it wont be featured in the game. Also they are doing extensive research on rides, the guy in charge of the rides/attractions has being doing his research and for example produced an 8 page document on one coaster track and support system for the art team to ensure accurate.
-There will be massive amount of rides and coasters in the game, as of the start of Feb they stated that they had 40 completed rides and coasters with many more planned for the final release in Q4 of this year.
-Coasters will feature accurate track types and supports, so each coaster type will feature different supports based on the real ride designs. They also confirmed hybrid coasters (ie RMC) will feature in the game.