Trend in Alcohol-related Crashes Before and After the Introduction of Mandatory Breath Testing Among Commercial Truck Drivers

BACKGROUND: Since 2011, commercial truck drivers have been required to take alcohol breath tests at the beginning and end of their working hours due to their employers’ legal obligations. However, non-commercial truck drivers are not required to do so. We examined whether alcohol-related crashes had decreased after 2011 among commercial truck drivers. METHODS: Using police data, we conducted a joinpoint regression analysis to examine the trend in the proportion of alcohol-related crashes from 1995 through 2020 caused by commercial truck drivers (who were subjected to alcohol breath testing) and non-commercial truck drivers (who were not subjected to testing). The annual percentage change in this trend was also estimated. RESULTS: During the 26-year study period, truck drivers caused 1,846,321 at-fault crashes, and 0.4% of the crashes involved intoxicated driving. A significant decreasing trend in the proportion of alcohol-related crashes was identified among both commercial and non-commercial truck drivers in the 2000s, during which several legal amendments were made against drunk driving. The annual percentage change was −13.5% from 2001 to 2012 among commercial truck drivers, and −14.9% from 2001 to 2011 among non-commercial truck drivers. No decreasing trend was observed afterwards, despite the introduction of mandatory alcohol breath testing in 2011. CONCLUSION: The effect of mandatory alcohol breath testing on reducing alcohol-related crashes among commercial truck drivers was not evident.