As to the technology required, both chemical and production science packs?
Maybe consider adding startup option to make them only require automation and logistic science packs? Would be nice to have the signals available when constructing the rail system, especially since it offers new ways to layout the tracks.

The cost of technology and recipes is an open question, but it is meant to be an upgrade to regular signals, so red and green science is probably not a good idea.
Currently the technology has the same cost as elevated rails, which i think is fine. Maybe it could be moved to blue science, but i think i meed more feedback.
Making chain signals take blue circuits instead of red circuits is an odd decision in hindsight though, i think i'll change that.

No worries, just a thought that occurred while I was testing. Well done!

Moving it to blue science sounds good. Right now it requires space and production science if you are running Space Exploration, so you could potentially be100+ hours into your game until you have the technology required.

I think its good for vanilla, but i can definitely adjust the cost for overhauls. I can make it take only blue science in SE. And probably only Logi Science in Py. Suggestions are welcome for cost of technology and recipes in other mods.