PRT, personal rapid transit, has arrived in Minnesota - at least a small version. A sixty-foot length of guideway and a prt vehicle are being assembled in Fridley. Building the prototype marks thirty years of effort by retired University of Minnesota engineering professor Ed Anderson, one of prt's best known boosters. Personal rapid transit is not new. A system is running in at least one American city. Others, including Minneapolis, are taking a wait-and-see approach. Minnesota Public Radio's Dan Olson reports.