An American Transportation Research Institute study, released on April 29, indicates that the 34-hour restart provisions (which currently remain under suspension) had a negative impact on motor-carrier safety when they were in effect by driving up truck crash risk.

The results of ATRI’s analysis “appears to support the contention that the July 1, 2013 restart rule did, in fact, have the outcome intended by FMCSA; that being the shift of truck trips from nighttime driving to daytime driving,” stated the authors, Daniel Murray, vice president of research, and Jeffrey Short, senior research associate.

“However, the unintended consequence of higher numbers of crashes at other points in the driving schedule also appears to have occurred,” they continued. “What is presently not known is whether the net direct costs of the post-July 1 crashes are higher than any ostensible benefit that might be associated with the driving shifts [that resulted from the rule change].”

ATRI analyzed an extensive truck GPS database to identify changes in truck travel by time-of-day and day of the week that may have occurred after the July 1, 2013, change made to the hours-of-service restart provisions by the Federal Motor Carrier Safety Administration. The group also examined several years of pre- and post-July 1 federal truck crash data to quantify safety impacts resulting from the HOS rules change.

Per the authors, the truck GPS data analysis identified a shift of truck traffic from nighttime to daytime and a shift of truck traffic away from the weekends to more congested weekdays, with the biggest decreases in truck activity occurring on Sunday nights.

What’s more, the analysis revealed a statistically significant increase in truck crashes after the July 1, 2013 rule change, specifically with injury and tow-away crashes. "In particular, the increase in injury and tow-away crashes would be expected based on the shifting of trucks to more congested weekday travel due to increased traffic exposure.”

The authors argued that overall economic improvement is not the cause of the crash increases and operational shifts because the statistical tool used percentage change, and tonnage growth percentages over the two-year period were relatively constant. They also said that truck unit-position points are a better indicator of physical truck movements than freight volumes.

The report includes some possible explanations for the GPS and crash data findings as a result of the operational changes fleets had to make after the new restart provisions went into effect. These included:

• Drivers abandoning use of the more restrictive 34-hour restart in favor of the rolling recap.

• Expanded use of “weekend productivity” by drivers, particularly Friday into early Saturday driving.

• Earlier weekend dispatches for drivers to avoid disruptions to early week (Monday-Tuesday) operations.

"After many years of crash decreases, everyone knows our industry has experienced an uptick in crashes," Dean Newell, vice president of safety for Maverick USA and a member of ATRI's Research Advisory Committee, observed in a statement. 

Newell said the ATRI research validates changes in operations and crash risk that seem to be associated with the restart rule. “Regulations should serve to improve safety, not create additional safety risks," he added.