Linking Carrier Descriptive Attributes to Crash Patterns: An Untapped Tool in State Motor Carrier Safety Improvement Programs -- A Comparison of Single Unit Truck and Combination Unit Truck Fatal Crashes

Historically, the classic paradigm for studying the underlying causes of commercial vehicle crashes has been to focus on driver, vehicle, highway, and environmental factors as the bases for identifying reoccurring or prevalent patterns. There is another, untapped data source: carrier attribute/descriptive data that can be obtained from the Federal Motor Carrier Safety Administration’s (FMCSA) Motor Carrier Identification Report, MCS-150. This study linked data from the MCS-150 file with single-unit-truck (SUT) and combination-unit-truck (CUT) fatal crash data in Virginia from 2005–2009 to yield a more expansive list of factors for consideration and analysis. The results indicate that the fatal crash patterns of SUTs were markedly different compared with those involving CUTs. Many more of the crashes of them involved carriers domiciled in the State of Virginia. The vast majority occurred on non-interstate highways, whereas the majority of CUT fatal crashes occurred on interstates. The fleet sizes (i.e., number of trucks operated) of carriers operating SUTs involved in fatal crashes were generally smaller compared with those of fleets operating CUTs involved in fatal crashes. Far fewer of the SUT crashes involved for-hire carriers; proportionally, more were private or “other” type carriers. The majority of SUT fatal crashes occurred very near to the carriers’ business location, whereas the crash location distances of CUTs ranged more widely. Far fewer SUTs involved in fatal crashes were hauling general freight compared with CUTs; SUTs generally hauled a much broader range of commodities. The results suggest SUT carriers are small businesses that operate locally/regionally and face significant risks and safety challenges due to the highway environments in which they operate. New ways to assist them need to be explored. Additionally, since the crash and operational patterns of SUTs are so different compared with those of CUTs, the safety trends of these two distinct vehicle types ought to be analyzed separately, rather than together as large trucks.