GTR employs track mathematics to create 36 tracks. Each race course changes as the difficulty level increases. Barriers appear and disappear. Race courses reverse. Bridges turn into jumps.
Alternate routes appear and shortcuts appear.
The weather changes. It does feel as though you are racing on a different track on each level. The only connecting factor is the location of the track itself. Environmental changes vary from rain to snow to sandstorms that create fog, mist, thunderstorms, tornadoes, floods, blizzards, whiteouts, and drifts. Each can vary in intensity and their effect on visibility and driving conditions.