Well as they said, graphical editors will be your best friend.

EDIT: If you are looking for a free cool track editor I would recommend getting the videogame Trackmania Nations Forever. It is free ( http://www.trackmania.com/index.php?rub=downloads ) Click the upper picture, "Free version". In this game there's a track editor which can build dirt and asphalt tracks. I am sure you can use this game to create something fun! Tracks with ramps, turns, slopes, bridges etc. Then of course you can test drive the tracks