Maybe in a place like NYC, but in most places mass transit makes it harder for auto's. In some cities the empty buses slow down traffic and get in the way. In Houston the train tracks were built ON roads, that does not relieve congestion.
Austin TX wants to build a train that will go a few miles into downtown at an exorbitant cost. Who benefits? It will most likely be built on a road. Why should taxpayers pay out the nose for the few hundred people who would ride this train?
Well removing a lane for a train is stupid. I did see something interesting from South America several years ago. A tv show explaining how some cities down there work. Special high speed buses with special bus lanes. They operate in an express mode and don’t stop every other block. They have trackers that are computerized and the lights are synced to them. They simply move you from point a, to point b fast. They were saying LA was going to do a pilot program on that. I wonder how it turned out.