THE ANTI-SCHOOL BUSING rider that zipped through the House last Tuesday is either so broad it is a total reversal of federal policy or so narrow it is superfluous. Either way, it deserves to be killed by the Senate.

The rider, attached as usual to an appropriation bill, forbids the Department of Justice to bring "any sort of action to require directly or indirectly the transportation of any student to a school other than the school which is nearest the student's home" except in cases in which the student is mentally or physically handicapped.

Since any school desegregation case can result in a judicial order requiring busing, one interpretation of this rider is that is forbids the Department of Justice, and thus the federal government, to initiate any more school cases. If that is what it means, it is an effort to put the financial burden of school litigation back onto minority groups and put the Justice Department's civil rights division on the sidelines when school matters are discussed in court.

A second possible interpretation is that the rider permits the Justice Department to continue bringing or participating in school cases but prevents it from suggesting to the judges that busing might be an appropriate remedy. If this is what it means, it is probably unconstitutional as a limitation on the department's responsibility to enforce the law and, given recent statements by the attorney general, unnecessary.

In a recent speech setting forth his views on civil rights, Attorney General Smith came close to forswearing busing and mandatory quotas as acceptable solutions to segregation problems. He said he was changing the department's policy in school cases from one that insists "the only and best remedy for unconstitutional segregation is pupil assignment through busing" to one that will propose whatever remedy has the "best chance of both improving the quality of education . . . and promoting desegregation."

Mr. Smith's description of past policy is somewhat exaggerated: almost nobody has ever asserted that busing is the "only and best" solution. But the attorney general's description of the policy he intends the department to follow while he is in charge should satisfy all but the most violent critics of school busing.

Busing of school children, after all, is a peculiar thing. It is critical to the operation of almost every school district in the country -- segregated, desegregated or otherwise. Even a county as urbanized as Arlington buses children all over the place, mostly to improve the quality of the education available to them. There may be times when busing is an essential par to any desegregation plan, and there may be times when desegregation can be accomplished without it.

It seems exceptionally shortsighted for Congress to be considering legislation to tie the attorney general's hands on so important an issue just when he has promised to do something about it. Actually, if the broader interpretation of this anti-busing rider is accurate, it would bar the Justice Department from proposing to the courts those "better remedies" that Mr. Smith has promised.