I managed to increase the draw distance by changing the value of MONSTER.EXE memory addresses 0064CFB0, 0064CFB4 & 0097BC54 from 20 (100% visibility) to 40. 20 being not the total of tiles displayed but the distance between your truck and the horizon, represented in textures.
<center>
Normal
Increased
Normal
Increased
Too many objects error
</center>
As you can see, the number of tiles (or textures) displayed won't increase more than 1 or 2 rows (of the 20 tiles limit), different thing happens with models, the game will display models that are farther than 20 tiles. (+10 tiles farther probably). However, some tracks will become unraceable because of the on-screen object limit. (Farm Road for example, if you look at the barn side the game will hang and show the too many objects limit).
This trick works in software and hardware mode (tested with Direct3d rendeering, should work with 3dfx). In hardware mode, some snow-like balls will randomly appear in the sky while you have an increased draw distance. If you set the values back to 20, the snow balls will appear, but they will move more slowly. They disappear after restarting the game.
After ending a race, and starting a new one, all models and terrain of the track will be white. This is fixed by changing the screen mode.
You can edit the memory addresses values to have an even smaller draw distance, not available in the graphic options, like 5 or 6 tiles (25% visibility)
advice: memory editing is hacking and it is illegal for multiplayer tournaments