Kevin Yee got me interested in finding some other examples of Alpine type gravity coasters. Here's a tamer looking one.
/www.parkcitymountain.com/summer/summer-activities/alpine-coaster
When I was a kid this park in Germany had a half pipe style with a sled that ha a brake, looks like they replaced it with this:
http://www.youtube.com/watchv=8d8eFgNDN1Q&feature=youtube_gdata_player
This looks intense also, would never work in USA, we lack the personal responsibility...
http://www.youtube.com/watchv=nxSgJSYdb3Q&feature=youtube_gdata_player