Shortcuts in Racing Games
While a shortcut can be found and used in a number of different ways, such as a hidden way to skip a certain level, boss, or event, shortcuts are often seen in racing and action sports games. While some are downright obvious, (Such as the one shown above in Wario Stadium,) others require a keen eye. In the games that offer them, clever racers can shave seconds off their lap times or find a fun jump route in a variety of ways.
Often just an alternate route that requires not much skill to find or use, these shortcuts are out in the open and sometimes even labelled with arrows. Some are found within the Mario Kart series.
Often found when slowly searching a track in a free ride or looking up in a guide, these shortcuts are meant for the observant driver in mind. Many are found in the Need For Speed series.
These shortcuts often are the ones that shave off the most times, as they usually require split second timing and precision to accomplish, such as some of the "Super Jumps" in Burnout Paradise or the Mushroom Boost Jumps in the Mario Kart series.
These routes are ones where something special must be done in order to use, be it activating something by driving on it, slamming a rival into it, or, blowing the crap out of it with an RPG. There should be many of these in the upcoming game Split/Second.
These are routes and tricks that possibly even the developers didn't intend to have, be it using a special car or item to launch over a giant section of the track. There have been many of these in the earlier Mario Kart games, but as time has passed, they've become much more rare.