A random sample of Oregon motor carriers was selected to determine the effectiveness of the Accident Countermeasures (ACM), a process created to address the factors involved in truck accidents and recommendations a motor carrier may utilize to prevent future similar accidents from occurring. Two groups of fifty motor carriers were selected, one group with a record of no accidents in a 12 month period and a group of 50 carriers who had accidents in a 12 month period. All 100 carriers were interviewed. Half of the accident groups records were reviewed and the recommendations of the ACM were supplied to the carrier, the other half was utilized as the control group. Follow up data was collected for the following year and analysis was completed to measure the effectiveness. A total of 82 Oregon based carriers remained in the study throughout its completion. The method of multiple linear regression was utilized to determine whether any variables in the set of explanatory variables considered in this study are related to the accident rate of a company. Data indicates the effect of the Miles Per Vehicle Driven in 1994, Percent of Miles Driven in Urban and the Total Out of Service are statistically significant for the Accident Rate in 1995 for the control group and the study group. It appears however, the estimated difference is only practically significant for the Miles Per Vehicle Driven in 1994 (F=20.31, p=.0001). There is no evidence of a relationship between a trucking companies accident rate in 1995 and the Accident Counter Measures intervention program. (F=.18, p=.67) The difference between the mean accident rates for a company which received the accident counter measure intervention and a company that did not receive the accident counter measure intervention ranges from -.98 to .75 (95% Confidence Interval for the difference of means). / Graduation date: 1999