for the nerds in the house, here is a real big number.
assuming a controller with 8 bit resolution (which is probably a low estimate):
256 possible steering wheel positions
x 256 possible throttle positions
x 256 possible brake positions
x 3 possible shifter positions (up/down/no change)
= 50,331,648 possible driver inputs per sample
100 hz lfs clock rate
x 100 second estimated lap time
= 10,000 time slices per lap
so to test all possible lines for ONE set, the LFS physics engine would have to calculate the car position 50,331,648^10,000 times, a number that is too big for my computer to even calculate.
even running such a simulation for just 0.1 seconds would hit the physics engine 1.04E+77 times, and a longer simulation would increase the number of calculations exponentially.
if someone where to attempt it, they could save a lot of computational steps by aborting laps that are ruined by going off track, but even chopping the work down to 1/1000th or 1/1,000,000th would still leave a rediculously vast number of laps to calculate. and remember, this is just for one setup. there are millions of possible setups. to test them all would simply be impossible, even using the worlds biggest super computers.