WASHINGTON, D. C. – Driving after a break appears to be one of the greatest traffic risks for commercial vehicle drivers, according to a recent study.

The study, conducted by the Virginia Tech Transportation Institute (VTTI) and funded by the Federal Motor Carrier Safety Administration (FMCSA), indicates that there is a potential for a “safety critical event,” not only on the first day, but also within the first hour – according to previous research funded by the same agency – which shows a “trend” between the two studies, according to one of the researchers.

The most recent VTTI “naturalist truck driving study” suggests that driving after a two-day break is a potentially risky period for a “safety critical event” (SCE) which could be a “crash, a nearcrash or a crash-relevant conflict,” according to the study terms.

Researchers don’t know why that first day after a break is so potentially risky for a SCE, but they now have a great deal of data that will allow them to further analyze that type of activity and how it might be contributing to the truck driver’s crash or conflict.

“That gives us a clue, or some information, that something is happening during their off-duty period,” says Myra Blanco, a researcher with VTTI.

“They’re potentially carrying over what they do during their vacation time – their off-duty time – that may be potentially affecting their driving performance. This is consistent with the results of a previous study that was performed at VTTI, where drivers were evaluated in a similar manner, when they were sleeping in the sleeper berths of the tractors.”

The previous study was funded by the FMCSA and announced in April.

The FMCSA said it will continue to explore the relationships between the two studies.