Also did an article on taking 360 screenshots in Unreal using this scene. Check it out here: https://cubebrush.co/blog/360-screenshots-in-unreal-engine
Here is a brief overview of the spline setup in the scene. Also this scene will soon be available for purchase on the Unreal Store! For now it is available at Cubebrush: http://cbr.sh/ej7iz6 and Gumroad: https://gum.co/subwaytunnel https://www.youtube.com/watch?v=mKRrLJ4kmFE