system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does the gravel under train tracks stay level so the train doesn't make it slide?
gpt
More than anything, the tracks themselves are made using strict guidelines. This helps to keep the weight distributed well across all the wood at the bottom and in turn the gravel/dirt underneath it. The gravel also does a very good job of holding the dirt underneath in its place keeping it from moving around.