I know the US has sucky trains, but commuter rail in Massachusetts is not electrified, so it is pretty dirty. I also recall a study of diesel busses running reg

I know the US has sucky trains, but commuter rail in Massachusetts is not electrified, so it is pretty dirty. I also recall a study of diesel busses running regularly scheduled routes. Because the load factor over the whole day is low, buses do not save much if any fuel or emissions. Solving the above problems plus being on-demand and door to door is a huge benefit.