In this year of COVID-19, medical conditions dominate front-page headlines. But it is in the back pages of the Federal Motor Carrier Safety Administration’s website where you will find evidence that medical conditions and their treatment are directly linked to highway safety.

In June 2020, FMCSA published a study by the Virginia Tech Transportation Institute (VTTI), “Commercial Driver Safety Risk Factors,” tracking nearly 21,000 truck drivers for three years. VTTI looked at the drivers’ medical conditions, age groups, personal attitudes and behavioral history and compared those factors to their driving records – specifically, crashes and moving violations.

Not surprisingly, VTTI found that drivers who exhibited risky behavior in one aspect of their lives tended to also take risks when driving a truck. For instance, drivers who did not use their seat belts regularly were between 45% and 234% more likely to be convicted of a moving violation.

Conclusions on the impact of truck driver medical conditions, specifically their treatment, on highway safety jump out from this study. VTTI found that obesity is far more prevalent among truck drivers than in the general working population, 58.4% versus 30.5%, respectively. But the study also found that obesity itself does not make a driver unsafe. Rather, it is the medical conditions associated with obesity that are safety factors.

Most Americans know that obesity related medical conditions include obstructive sleep apnea (OSA), high blood pressure and diabetes/elevated blood sugar. Those conditions can be linked to the increased risk of crashes and moving violations. For example, drivers aged 34-42 with untreated OSA are 78.6% more likely to be convicted of a moving violation than drivers in the same age group who did not have OSA.

Similarly, truck drivers use more tobacco than the general working population, 60% versus 18.9%. But it is the comorbidity factor of lung/chest disease which correlates to safety risk. Drivers over age 52 with untreated lung or chest conditions are 3.72 times more likely to be in a crash than are similar age drivers who do not have those medical conditions.

Fortunately, the commercial driver medical examination (required at pre-employment and typically every two years thereafter) will reveal whether the driver has any of the medical conditions which contribute to increased health and safety risk. This is fortunate for two reasons. One, it shows that the FMCSA medical exam is properly identifying safety risks. And two, drivers, and their employers then have the opportunity to seek treatment to improve these conditions. And the VTTI study shows that treatment can actually improve highway safety.

For example, drivers aged 34-42 with treated OSA are 95.9% less likely to be involved in a preventable crash than drivers without OSA. Drivers in the 43-51 age group with treated diabetes/elevated blood sugar are 50% less likely to be involved in a crash compared to drivers without that condition.

VTTI found even more dramatic comparisons between drivers with treated medical conditions and drivers with diagnosed but untreated conditions. For instance, drivers aged 43-51 with treated OSA are 68.9% less likely to be in a preventable crash than diagnosed but untreated drivers of the same age group.

Certain medical conditions, left untreated come with increased safety risk in life and on the highway. But treatment for those conditions actually leads to improved highway safety.