People along the Northstar Corridor got a "bells and whistles" preview of commuter rail today . Northstar officials gave rides on commuter rail cars similar to those that will carry commuters on the proposed Northstar Rail Line. The 70 mile corridor is already set up for rail traffic, so supporters say it's just a matter of moving trains onto the tracks. But some people think the Northstar line is an inefficient use of money, and that it won't ever carry enough passengers. Minnesota Public Radio's Tim Post reports.