Gradient Filter for specific shape?

Question

I have the following picture and I am interested to create a vignette along the rails.

To achieve this, I added a curves adjustment layer and lowered the brightness for my midtones and dark areas.

For the straight part of the rails, I was able to create a vignette by applying the gradient filter like this:

For the bottom, I have only managed to use the lasso tool to create a mask for the bottom layer with a high feather to achieve this:

Unfortunately, the effects aren't as good as the gradient tool. Is there a way to apply achieve a similar effect with the gradient tool for the bottom part of the image?

Answer 1

Maybe try filling a square with a linear gradient that goes from white to black to white, then do a perspective transform on it.