Common to all track files are bytes that refer to the item that is to be modifed. For example, the byte following a 99 in a file usually represents the right-hand wall height.

All values are in hexadecimal.

0x80 - place object
0x81 - forward view distance
0x82 - backward view distance
0x85 - track width change
0x86 - Pit entry joins this segment
0x87 - Pit exit joins this segment
0x8A - Track markings type A
0x8B - Track markings type B
0x8E - Left kerb
0x8F - Right kerb
0x98 - Left fence height change
0x99 - Right fence height change
0xA1 - Pit lane entry, join right pitlane fence
0xA2 - Pit lane entry, join left pitlane fence
0xA3 - Pit lane exit, join right pitlane fence
0xA4 - Pit lane exit, join left pitlane fence

More will be added as more are discovered.