Eric Ryan 808 is right.  The plan is for existing bus lines to be re-routed to the rail line.  Many of those who ride the rail will not be new mass transit users, but existing bus riders.  Furthermore, lots of those who now take one bus to get to where they want to go will have to take a bus to the rail  line, take the rail, then get on another bus to go to their destination.  The rail PR doesn't tell that side of the story.