Earlier today, I was doing some youtubing when it comes to Planet Coaster and I came across this video. In the video, he shows how he put the billboards to great use. You can start watching how he uses the billboard around the 2:45 mark. He has a number of videos of his WIP park and I like the way he is going with it. However, I think if he puts too many billboards in the park. It wont be playable at all as I have read that billboard are a frame rate killer. no matter how good the PC is.
https://www.youtube.com/watch?v=rBC84D3nCss
https://www.youtube.com/watch?v=rBC84D3nCss