I am just a Bill on Capitol Hill

I rewatched Schoolhouse Rock with my kids last night. I had not realized that the Bill, sitting on Capitol Hill, was in fact a bill to make school buses stop at railroad crossings. I don’t know if this is an actual federal law, or there is some federal monetary incentive to ensure states pass such laws, (Spoilers: in the cartoon, it is in the end passed), but it is a state law almost everywhere.