This document incorporates a Safety Fitness Rating Methodology (SFRM) as an appendix to the Motor Carrier Safety Fitness Procedures regulations. The SFRM will be used to measure the safety fitness of motor carriers against the safety fitness standard contained in 49 CFR Part 385. By this action the FHWA will supersede the interim final rule promulgated on May 28, 1997, effective May 28, 1997 until November 28, 1997 (62 FR 28807). That rule incorporated an SFRM to calculate the safety fitness of motor carriers transporting hazardous materials in quantities for which vehicle placarding is required, or transporting 15 or more passengers including the driver. The rule also includes a procedure which provides a notice period of 45 days during which a proposed rating can be challenged before it becomes effective.