Section 642, Pub. L. 91–518, title VIII, § 802 , Oct. 30, 1970 , 84 Stat. 1340 , prohibited discontinuance of intercity rail passenger service other than in accordance with provisions of this chapter. See section 24705 of Title 49 , Transportation. Section 643, Pub. L. 91–518, title VIII, § 803 , Oct. 30, 1970 , 84 Stat. 1340 , related to separability of provisions of this chapter. Section 644, Pub. L. 91–518, title VIII, § 805 , Oct. 30, 1970 , 84 Stat. 1340 ; Pub. L. 92–316, § 11 , June 22, 1972 , 86 Stat. 233 ; Pub. L. 93–496, § 11 , Oct. 28, 1974 , 88 Stat. 1531 ; Pub. L. 99–272, title IV, § 4007(a) , Apr. 7, 1986 , 100 Stat. 108 , related to records and audit of National Railroad Passenger Corporation and certain railroads. See section 24315 of Title 49 , Transportation.