Louis J. Lefkowitz, Atty. Gen. of New York, Ruth Kessler Toch, Sol. Gen., Dunton F. Tynan, Asst. Sol. Gen., Matthew A. Tiffany, Asst. Atty. Gen., and Walter J. Myskowski, for appellant.

Solicitor General Marshall, Assistant Attorney General Turner, Howard E. Shapiro, Robert W. Ginnane and Leonard S. Goodman, for the United States and others.

R. J. Murphy and D. M. Tolmie, for appellee railroads.

William C. Sennett, Atty. Gen., and Edward Friedman, for appellee Commonwealth of Pennsylvania.

Eugene T. Liipfert, for appellees Port Authority of Allegheny County and others.

PER CURIAM.