Nos. 94-3014, 94-3072. Argued July 20, 1994. Decided September 30, 1994. Mark J. Mahoney, Larry G. Hall (argued), Matkov, Salzman, Madoff Gunn, Chicago, IL, for Yellow Freight System Inc. Aileen A. Armstrong, Deputy Associate Gen. Counsel, Frederick C. Havard, Supervising Atty., Fred L. Cornell, Jr. (argued), N.L.R.B., Washington, DC, for N.L.R.B. Petition for review from the National Labor Relations Board. Before SCIRICA, LEWIS, and SEITZ, Circuit Judges. OPINION OF THE COURT SEITZ, Circuit Judge