Most 3D software has some form of object or model management, and "scene management" tools or palettes. You can group models or place them in a folder together, then toggle the group or "layer" off and on (hide or show) so you can work on specific models or parts of the scene without other models getting in the way. You can also isolate selected models, which hides everything else. 3DsMax offers several ways to do this, and Blender has similar options.
When working on a track in 3DsMax, I place the terrain, trees, barriers, buildings, road surface, mesh, etc., on their own "layers." As the model develops, additional layers are added to make smaller groups of models. Then I can toggle groups of models on and off as needed when I'm working on a specific group of models, like a set of buildings. 3DsMax also offers even more robust scene management (a different palette), so you can nest groups within groups. If using 3DsMax or Blender, you should be able to find some video tutorials to help you use these tools or features.
Blender Tutorials
3DsMax Tutorials