Sure, the area of highways is less but the impact is not localised. If you see the articles that I had quoted in my original comment, two of them mention impact

Sure, the area of highways is less but the impact is not localised. If you see the articles that I had quoted in my original comment, two of them mention impacts which bubble up to other areas as well. Also, it is not necessary that even area around highways has to be an eyesore/badly degraded. Mountainous roads are some of the most beautiful paths to travel on and there are plenty of examples where construction has happened keeping that in perspective.