That looks sweet! UE4 has a spline-based road tool also, but I've never used it. I tried to open S2's site from the link on YouTube, but it wouldn't open in any of my browsers. Down, maybe? It is a weekend, after all. Anyway, I will try again later. I am very curious what other features it has.
MAME Cab PC: i7 4770@3.4Ghz (passmark 9945), 12GB RAM, Win 10/64, GeForce GTX645 (passmark 1898); Shiny new laptop: i7 4800MQ@2.7Ghz (passmark 8586), 16GB RAM, Win 10/64, GeForce GTX870M (passmark 3598); Old laptop: i5@2.3Ghz, 8GB RAM, Win 7/64, Intel 3000 graphics