Half-pipe

From Mario Kart Racing Wiki

A half-pipe is a section of a track where it is possible to perform tricks on both sides of the road. The best example would be the final stretch of DK Summit, which features Shy Guys performing tricks on skis. In these terms, "half-pipe" means "half-cylinder", which is what a half-pipe road looks like.

Half-pipes are useful for prolonged boosts of speed since a racer can just drive constantly along the edge of the top without doing tricks.