While I heartily agree that we need the ability to toggle the elevated rails, you can work around it in situations like this by using a deconstruction planner with an appropriate filter set.

It's not ideal, but it will at least let you get at stuff under the rails without deconstructing the rails ...

Hi, recently I got into building a lot of rail intersections with the new elevated rails. I love the new posibilities, but i feel like there's a big issue with trying to build underneath the elevated rails, signaling is the issue to be exact.

Like on this picture of an actual intersection i built ...