I've not seen nfs but I'm guessing it's like any other race game.
This would mean you'd probably want to create the track out of a mesh or meshes created in a 3D modeller. Creating the whole track as one bit would probably be a bad idea as you're not going to see the whole thing at any one point so if you create it made of chunks then you can hide the bits you can't see and therefore increase performance.
Terrains are really if you're going to see a lot of terrain at the same and you have the ability to roam anywhere (like flight sims or 1nsane).
I would suggest creating the track in a 3D modeller, chop it up into chunks then show and hide as necessary to keep the surface and poly count down.
This would mean you'd probably want to create the track out of a mesh or meshes created in a 3D modeller. Creating the whole track as one bit would probably be a bad idea as you're not going to see the whole thing at any one point so if you create it made of chunks then you can hide the bits you can't see and therefore increase performance.
Terrains are really if you're going to see a lot of terrain at the same and you have the ability to roam anywhere (like flight sims or 1nsane).
I would suggest creating the track in a 3D modeller, chop it up into chunks then show and hide as necessary to keep the surface and poly count down.