CFR›Title 49›Subtitle B›Chapter VI›Part 665 ContainsSubpart A; Appendix A; Subparts B–CCorpusDaily eCFRDisplayed edition2026-04-23Last updated2026-04-23 PART 665—BUS TESTING Contents A Subpart A—General Sections 665.1–665.7 Appendix A to Part 665 Appendix A to Part 665—Bus Model Scoring System and the Pass/Fail Standard B Subpart B—Bus Testing Procedures Sections 665.11–665.13 C Subpart C—Operations Sections 665.21–665.27 Authority49 U.S.C. 5318 and 49 CFR 1.91.Source81 FR 50387, Aug. 1, 2016, unless otherwise noted. Previous 663 Part 663—Pre-Award and Post-Delivery Audits of Rolling Stock Purchases Next 670 Part 670—Public Transportation Safety Program