FMCSA proposes to amend parts 393, "Parts and Accessories Necessary for Safe Operation," and 396, "Inspection, Repair and Maintenance," of the Federal Motor Carrier Safety Regulations (FMCSRs) in response to several petitions for rulemaking from the Commercial Vehicle Safety Alliance (CVSA) and the American Trucking Associations (ATA), and two safety recommendations from the National Transportation Safety Board (NTSB). Specifically, the Agency proposes to (1) add a definition of "major tread groove," (2) revise the rear license plate lamp requirement to provide an exception for truck tractors that do not have a rear license plate, (3) provide specific requirements regarding when violations or defects noted on a roadside inspection report need to be corrected, (4) amend Appendix G to the FMCSRs, "Minimum Periodic Inspection Standards," to include provisions for the inspection of (a) antilock braking systems (ABS), automatic brake adjusters, and brake adjustment indicators, (b) speed-restricted tires, and (c) motorcoach passenger seat mounting anchorages, and (5) amend the periodic inspection rules to eliminate the option for motor carriers to use a violation-free roadside inspection report as proof of completing a comprehensive inspection at least once every 12 months. In addition, the Agency proposes to eliminate introductory text from Appendix G to the FMCSRs because the discussion of the differences between the North American Standard Inspection out-of-service criteria and FMCSA's periodic inspection criteria is unnecessary.