Hey Mario, Hard to know exactly why some things are done in aiw files unless you have signed a "non-disclosure" agreement with ISI (which I have not). Like pre-production work in entertainment, it's useful to do as much work as you can before the show, so you don't have to try to make it or figure it out during the show. With rFactor, the more of the environment, limits, and paths you can calculate in devMode and store in a static aiw file... the less you have to do during the real-time race simulation. If you tried to do all this in real-time (like the Mars Rover), your execution time would suffer. About your questions: (Read somewhere): wp_pathinfo2 is elapsed time since last wp, and wp_pathinfo2 is time in this sector 'so far'. (Guess..) Regarding why the orientation (pitch, yaw, roll in radians) at each path point.. on each wp.. for every drive line: Say you have 2 drive lines (fastest and block) that are on intersecting paths on a banked corner: -- At a certain waypoint, the Fastest line is pointing a little bit down the banking. -- At the same waypoint, the Blocking line could be pointing a little bit up the banking. So the car's loading, traction, aero, and a bunch of other things are different for each drive line... at the same waypoint. If rF can always know the approximate orientation of each ai path via pre-calculated ori, it saves processing time during the race. The simulation could also use it to mimic a real driver that can actually see the track.... software for the ai cars can 'look-ahead' at the ori, and 'know' when to brake for a corner, or speed up when the path is going to straighten out. It also 'knows' ahead of time how much the car weighs, how many micro liters per radian of crank-shaft rotation that the fuel usage is.... and bunch of other stuff in files for the various mods. Probably some pretty compelling reasons for independent ori for each line, or it would not have been a newly added set of parameters to each wp block in rf2 aiw files.