Charlotte Motor Speedway (roval)
Charlotte Motor Speedway became the home track of many NASCAR teams. It was also the first superspeedway that installed lights for night racing.
The Charlotte Motor Speedway built a new infield road course, designed specifically for NASCAR competition. It utilizes nearly all of the 1.5 mile oval as well as newly built infield portion hence the name Roval (Road + Oval).
Some more resources for a deep-dive: