Making Realistic C2 Terrain by CoffeyCup
Making some realistic scenery is easy using TerraGen, a shareware scenery generator. It's great for generating photorealistic landscapes, which can exported as 3d models.

The ability to import your own images lets you have control over what the landscape will be.

TerraGen uses heightmaps; an image where the brightness of each pixel is interpreted as the height at the pixel's coordinates. A white pixel is interpreted as maximum height, while a black pixel marks the lowest possible height value.
Example A gives a nice mountain pass with a roadway.

Example B would generate a lunar-like scene with craters

Example C a 3D face

You will be able to export the result as a Lightwave Object (.lwo) which can be converted to 3DS with 3DWin5
Set to it's lowest resolution output, TerraGen makes a 128 x 128 grid. Each square on the grid is made of 2 polys, so...

(128 * 128) * 2 = 32768 polys!!

That's a lot of polys.
Using poly reduction software like Action3D Reducer Pro 3.0.5 will get it down to 8423 polys.

At this point you're ready to bring it into to 3DSMax for some clean-up and scaling to size. Probably scaling down by 50% or more, depending on how huge your level is.
Using good tileable textures, sized just right, can really make a believable scene. Because the road was drawn on the heightmap, there should be polys that follow the road that will make texturing easier.

Once you have it looking presentable, you'll want to test it in the game. Driving is the best way to double check the size and see that the road is drivable or at least find the rough spots for fixing.
From 3DSMax, export as .ASE. Then use Cesm's ASE2ASC app to get it to an .ASC and ready to go right into Plaything 2.

See C2 Scientist and Econobrick's Track making tutorial at the The Spray Shop for putting the track in the game.

For these purposes, you only need the first section of the tutorial "Putting the track in the game" later,the rest of the tutorial will come in handy.