NATION - The Federal Transit Administration wants public transit agencies to get out of the business of creating routes designed exclusively to take students to and from school.

But a proposed policy statement, which the agency says only clarifies rules that have been in effect for more than 30 years, has raised alarm among district officials. For some districts, those officials say, public transit is the most effective way to get students to school.

Paul Griffo, a spokesman for the federal agency, said that a final proposal would be released soon, but that any changes the FTA makes would not be expected to affect school transportation for the 2008-09 school year. The changes are meant to ensure that transit agencies that receive federal money are only using the funds for general transit service, Mr. Griffo said in an e-mail message last week.

Some organizations are predicting dire consequences, however, if the FTA proposal is adopted.

"One transit agency reports the change would affect some 40 percent of its routes, another reports over 80 percent of its supplemental-service trips would be impacted, many schools report this proposal would result in a complete disruption of service, and in at least one case, an entire state system would suffer," said a letter in opposition to the proposal jointly submitted by the American Public Transportation Association, the National School Boards Association, the American Association of School Administrators, the Council of the Great City Schools, and the National Association of Secondary School Principals.

Private bus companies, though, are supportive.

In a letter to the FTA, the Minnesota School Bus Operators Association said: "We have seen school districts in the state who advertise local transit authorities as a contact for transportation on their district Web site, circumventing the local school bus operator entirely from the process. We have seen districts that call the local transit authority to bid on specialized school bus transportation.