Since the national launch of the Federal Motor Carrier Safety Administration’s (FMCSA) Compliance, Safety, Accountability (CSA) initiative, a handful of studies have attempted to study the degree to which motor carrier safety scores are related to actual carrier crash involvement. While each study offered numerous insights, the American Transportation Research Institute (ATRI) sought to expand on previous findings by utilizing a more targeted statistical analysis to answer two related research questions: Are percentile scores related to actual safety (i.e. crash involvement) ? ; and does CSA properly classify carriers according to crash risk (i.e. do carriers with 'Alerts' have higher crash rates than carriers without 'Alerts') ? According to FMCSA, high percentile scores in a Behavior Analysis Safety Improvement Category (BASIC) indicate a lack of compliance and greater exposure to potential safety problems, including crash involvement. That is, as scores go up, it is expected that crash involvement will also increase. However, previous researchers searched for, and failed to find, clear linear relationships between BASIC percentile scores and carrier crash rates. This study proposes that a simple correlational approach may simply be unable to detect the existence of a relationship due to the nature of the data under consideration. Crashes are infrequent events, and therefore special tools are required to model their occurrence. Relying on best practices in the field of statistics, ATRI’s analysis uses a rigorous statistical approach to provide a more accurate description of the relationship (or lack thereof) between BASIC scores and crash involvement. ATRI analyzed Safety Measurement System (SMS) and crash data for a sample of 471,306 motor carriers with evidence of recent activity in the past 24 months. Analyses focused on the five BASICs that are available to the general public. (Author/publisher)
Samenvatting