Rail penalty mod API

[Rednax]

Hello Factorio mods, devs and fans,

While reading through some of the suggestions for improvements on the rail systems, and combining that with my own experience, I wondered if mods had access to the rail penalties. This would allow the community to experiment with the various ideas that are floating around, and the devs can focus on other stuff. I could not find this in the API, so hence the suggestion to allow mods to set the penalty for rails. Either static, via entity prototypes, or even better, dynamic, via the Lua API.