I once heard that in the middle of 20th century, public transportation in the USA was widely privatized and bought by automotive manufacturers, and then wilfully left to rot, so that people would buy more cars.
However, I can’t find anything backing that up. Do you know whether that’s true, and where I can find some sources for that?
Public transit, in the United States, is primarily owned and operated by various government agencies.
What you are describing fits into the conspiracy theory that automobile manufacturers “lobbied” politicians to pass laws, subsidies, zoning regulations, public transit expansion plans, etc that would favor / encourage car ownership while limiting the growth of public transit. I believe that there where some trials involving auto manufacturing executives, which support at least part of this theory, but I don’t know those details.