Under the Administrative Procedure Act. 5 U.S.C. § 553 an agency's action in promulgating standards may be set aside if found to be 'arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.' 5 U.S.C. § 706(2)(A); Citizens to Preserve Overton Park v. Volpe, 401 U. S. 402, 401 U. S. 414 (1971); Bowman Transportation, Inc. v. Arkansas-Best Freight System, Inc., 419 U. S. 281 (1974). The rescission or modification of a standard is subject to the same test. Section 103(b) of the Act, 15 U.S.C. § 1392(b), states that the procedural and judicial review provisions of the Administrative Procedure Act 'shall apply to all orders establishing, amending, or revoking a Federal motor vehicle safety standard,' and suggests no difference in the scope of judicial review depending upon the nature of the agency's action.
Revocation constitutes a reversal of the agency's former views as to the proper course. A 'settled course of behavior embodies the agency's informed judgment that, by pursuing that course, it will carry out the policies committed to it by Congress. There is, then, at least a presumption that those policies will be carried out best if the settled ...