Hello, i want to ask, how do I make a regular descending rail for 500 meters?
What do you mean by "regular decending"? A constant rate of descending?
You can modify the parameters of the splines/tracks in which you can set the gradient at the beginning and at the end. Also if you rigth click on it and click on "constant gradient", it will convert it so the gradient is the same at the terminals of the spline (note that in this case there will be a bump at the connections with other splines).