Hello,
I have played with your mod and made it 4 lanes instead of 2, and changed the concrete to refined concrete. I will not publish it because its not mine. I am learning how to mod and find your code easy to read. I don't know how to make mod settings yet. I await your updates.

Thank you for this mod. :)

I'd rather just merge your changes in since I've made further changes as well. I'll sort out github and the forums etc. Give me a few to get organised.

Forum created. Put your zip there. I'll have a look and merge your changes in. thanks!

I posted it...I really wanted to make mod settings to choose the type of concrete and whether to have 2 or 4 lanes. Right hand Drive or Left Hand Drive. I also thought it would be cool to check "if [mod-exist]" Beautiful Bridge Railway and offer those modded rails as well as the mod Concreted Rails. Just thoughts.
I really didn't do a whole lot. Just messing around.
Thank you.

Hi, this link should help you: https://wiki.factorio.com/Tutorial:Mod_settings

At the bottom your idea of if [mod-exists] is explained.

Nice mod idea btw.