How much staff assistance does an administrative law judge need before making a threshold decision of whether an impact statement is required?

We are reminded by Mr. Justice Harlan that guideline decisions 'suffer the danger of pitfalls that usually go with judging in a vacuum. However carefully written, they are apt in their application to carry unintended consequences which once accomplished are not always easy to repair.' Sanders v. United States, 373 U.S. 1, 32, 83 S.Ct. 1068, 1085, 10 L.Ed.2d 148 (1963) (dissenting opinion). It would therefore be inappropriate for us to suggest how much staff assistance the administrative law judge should have in individual cases before he makes the threshold decision of whether an impact statement is required. There may be cases in which no assistance would be necessary. ³ But we remind the ICC that under Hanly II it has an affirmative obligation to develop a reviewable record of this threshold determination, see 471 F.2d at 836, and its decision on this matter must be sufficiently reasoned so that a reviewing court can determine whether or not it was arbitrary or capricious, see 471 F.2d at 831.

Accordingly, the order of the district court is affirmed.