In 1991 the Federal Highway Administration, which at that time had regulatory responsibility for trucking safety issues published a Commercial Vehicle Preventable Accident Manual with assistance from a contractor, Triodyne, Inc. This manual incorporates and updates much of the advice from that 1991 publication. Since 1991 many changes have been made to the Federal Motor Carrier Safety Regulations, now administered by the Federal Motor Carrier Safety Administration (FMCSA). One of the most significant changes is the adoption of the motor carrier safety fitness rating system. Fitness ratings of Satisfactory, Conditional or Unsatisfactory are assigned to each carrier, based upon a six factor algorithm. The sixth factor in the formula is Accidents, defined as the ratio of recordable accidents per million miles. Prior to amendment of the formula in 1997 the accident factor had been determined by the ratio of recordable/preventable accidents per million miles. The agency decided to use the ratio of recorded accidents because its studies had shown that over time the ratio of recordable/preventable accidents to recordable accidents had been stable. However in making this regulatory change the agency indicated that it might make some allowance in the course of assigning a rating if a carrier demonstrated "compelling evidence" that the recordable rate is not a fair measure in its particular circumstances. For that reason it may be helpful to carriers to have a systematic determination as a part of their safety program as to whether each accident was preventable. More importantly the process of making preventability determinations may tend to highlight areas in which improvement can be made in the overall safety program. It also may reveal areas in which attention should be devoted in the process of driver safety training. Preventability determinations are helpful in according recognition to safe drivers, and conversely they may help to identify drivers in need of retraining or other corrective action. Some carriers have adopted a practice of assessing "deductibles" against drivers when bad driving practices have cost the company money. If any of these practices are followed, it is essential to have some guidelines that are to be followed in making preventability determinations.