Jefferson County Public Schools officials say Tuesday's start of the school year has been relatively smooth for the system's students, faculty and staff.Nearly 100,000 youngsters are enrolled for the new academic year.A new student assignment plan for elementary school students approved by theschool board in May won't go into effect until the 2009-2010 academicyear, but JCPS Superintendent Sheldon Berman says it shouldn't cause amajor disruption."We will actually have probably two sets of bus routes next year, because we'llbe grandfathering a number of students in. But i think the changes will be subtle,and they will not be as evident, or stark as people may gather. I think we'll seean evolution over time," Berman said.Officials are now working on new plans for middle and high schools.A change in the JCPS student assignment plan for all students was mandatedin a U.S. Supreme Court decision last year.