Maybe I can shed some light on this topic about racing games and the race tracks they contain. And in particular, simulated versions of Infineon (Sonoma Raceway), Thunderhill and Buttonwillow.
First of all, only iRacing contains a native version of Infineon (none of the others) but you have to purchase iRacing base game and then buy tracks individually. We don’t use it here at our sim training center at Infineon (many reasons too numersous to list here).
rFactor is also a “base racing game” that you must install tracks (and various cars) into it and that can be tedious if you are not computer-savvy. But it isn’t that hard. The problem with rFactor Racing Game is the tracks are not built by 3D gaming professionals. They are built by “users” who have variable skills (some are real racers but not many). In general, rFactor tracks are somewhat comic-book (some worse than others) and have in-accuracies in track configuration (turn radius, camber, placement of curbing, etc.). They are fun to drive of course, and perhaps can be used to learn at a superficial level of where the track goes left/right/straight, but that is about it. rFactor does have Infineon, Thunderhill and Buttonwillow available for download install but on a scale of 1-10 (10 best) I would give them a #5 or less racing (in other words, pretty comic book stuff).
GTR2 is another native racing game that is a little more serious than rFactor and has tracks also available for download and install. Generally speaking, tracks in rFactor have also been converted to users to run in GTR2 - but they are still the same level of comic-book ratings.
GTR2, iRacing and rFactor take a pretty stout computer system even by today’s standards and of course if you use cheap store-bought controls (wheels/pedals) you are pretty much wasting time for anything other than just have fun playing a racing game on your computer.
And Rob Rhodes is correct about the cost of building simulated racing tracks being extremely costly in both money and man-hours. iRacing for example uses a laser imaging device which produces a point-cloud of the racing surface and objects. And that takes days to capture the data and then hundreds of man-hours to add textures and process it for use in a racing game. Based on known averages and my experience with scope-of-work for building simulated tracks (I’ve been building simulated tracks myself as a “user” since 1998) I would guess an iRacing individual track would cost between $50K to $75K to get it in-game. I built a from-scratch version of Infineon for our training simulator and have about 1600 man hours in the project. Even at a cheap labor rate for 3D modeling and textures of $75/hour…that’s about $120K in costs!
Simulated racing tracks are not cheap to acquire!
I could write many pages on this topic but hope that helps put things in perspective for you guys who asked about tracks in racing games.