CFR›Title 23›Chapter I›Part 646 ContainsSubparts A–BCorpusDaily eCFRDisplayed edition2026-04-24Last updated2026-04-24 PART 646—RAILROADS Subparts A Subpart A—Railroad-Highway Insurance Protection Sections 646.101–646.111 B Subpart B—Railroad-Highway Projects Sections 646.200–646.220; Appendix to Authority23 U.S.C. 109(e), 120(c), 130, 133(d)(1), and 315; 49 CFR 1.48(b). Previous 645 Part 645—Utilities Next 650 Part 650—Bridges, Structures, and Hydraulics