Chris Sawyer acted only as a consultant on the last game developed by Frontier. Atari recently stated on their forums they are thinking about Rollercoaster Tycoon 4 and are asking fans to suggest ideas for the next installment.
Get a kit, and set it up.... There are certain places that you can get a roller coaster kit. Now I had to order mine from FUTURE INVENTORS of AMERICA. You may not have one where your at but there are other places you can get them at. Just look and you find one.