Developing and Testing a Dynamic Theory of Motor Carrier Safety

Developing an understanding of the longitudinal relationships between different measures of motor carrier safety is important to advance theory and practice regarding this significant supply chain management and public policy issue. In this article, we combine core principles from several theoretical traditions to propose a dynamic theory of motor carrier safety that specifies the longitudinal relationships between three core measures of safety publically reported by the Federal Motor Carrier Safety Administration: unsafe driving, hour-of-service compliance, and vehicle maintenance. We test this theory using fouryears of longitudinal data on motor carrier safety for a random sample of large, for-hire motor carriers. Results from fitting a vector multivariate autoregressive moving average time-series model are largely consistent with the theory we propose. We describe the implications of our research for supply chain management theory and practice, summarize limitations, and suggest directions for future research.