International Speedway Corporation (ISC) is a corporation whose primary business is the ownership and management of NASCAR race tracks. ISC was founded by NASCAR founder Bill France, Sr. in 1953 for the construction of Daytona International Speedway and in 1999 they merged with Penske Motorsports to become one of the largest motorsports companies in North America. The company has played an important, though controversial, role in the modernization of the sport. It has worked with NASCAR to create new tracks and update older ones in an effort to improve the racing and the experience for spectators (though because both companies have several members of the France family in top positions, ISC's competitors have filed multiple lawsuits on antitrust grounds) and has constructed popular new tracks in regions previously thought uninterested in NASCAR (though this has upset some residents of nearby towns who do not want a NASCAR track in their back yard).  Wikipedia