Assertion: coaster's track | /r/MadeOf | concrete
Facets:
value: usually
type: TEMPORAL
Source sentences:
text: There are two main types: an Alpine coaster or mountain coaster is a type of roller coaster where the sled runs on rails and is not able to leave the track, whereas with an Alpine slide the sled simply runs on a smooth concave track usually made of metal, concrete or fiberglass.