Obtaining the various drivers licenses alone requires near perfect driving skills, and you'll need to be able to drive these courses with your eyes closed if you hope to win the races.
It's not a perfect simulation of driving in the same way Sega's own "Ferrari F355 Challenge" is, but it's close -- and with a lot more cars and races to choose from.
Dig below the surface however and you'll find the kind of depth that'll take weeks or even months to fully explore. A shameless clone of Sony's "Gran Turismo," and a a pretty good one too.
SummarySega GT attempts to capture some of Gran Turismo's formula for the Dreamcast, but it ultimately falls short due to poor control and an unintuitive interface.