The Frontend is the Main Menu of Re-Volt. The frontend has a theme of a closed toy store. It can be made driveable in by renaming everything to some other level and fooling the game into thinking it is a track.
Although when playing this track, there is no collision on anything except for the floor. Also another noticeable problem with this track is that the car boxes' textures are garbled. Instead load the carbox files, it substitutes them by the fxpage images, like the road signs. The start position type is "2". This type is programmed to set the cars in their proper places in the frontend: The three first cars on the Clockworks Table, the fourth car next to the boxes stack, and the rest in the center.
Frontend appears to contain a short racing line, where cars turn around the counter of the store. Also, developers planned to create a training mode using this track, but the idea didn't come true. This mode appears in old demos of the game.
Custom Frontends are also possible by replacing the frontend folder. One example is Sakura Frontend created by Hilaire9.