This reminds me of the Ames Slide on the RGS. The cause was the beaver dams up the hill. The RGS took care of the beavers and their dams and then sent the slide on down the hill farther. This was Victor Miller's first task as Receiver.
Unlike the RGS, the problem is the ground subsiding but the solution is about the same, kill the beavers! (Just kidding!) Put in proper drains up the hill where the road is collecting the water, perhaps piping the water down below the railroad grade to help dry out the ground in this area. Once the ground is dry, the tracks can be fixed and straightened. Perhaps putting in piles would help ensure stability of the ground. This sounds like a good chore for the new commission!
Installation of proper drains could be done without much disruption of traffic on the road or railroad and should cost less that having to continuously repair the road and railroad. (I wonder why they didn't do that to begin with - they really need to pay attention to the geologist!!!)
Just my $.02.