If you need to create road in 3ds Max that winds through the mountains, here you can see several ways for its creation.
The first method is through a script called Terrain Conformer. You can download it from Scriptspot and see how to work with it from the video below.
The second way is “cleanâ€, without using any scripts. This method was presented by Xoio and offers a greater control over the shape of the road after its placing on the terrain. More information you can get from the video, they have done.
In Viz-People`s webpage i found another way of modeling road in Max, again without using any scripts.
Source:Â Mladengradev