The American Transportation Research Institute on Tuesday released the findings of its evaluation of the Federal Motor Carrier Safety Administration’s field study report on the new hours-of-service rules.
The Federal Motor Carrier Safety Administration was directed by Congress to study the effects of the restart provisions within the work rules, which were revised and went into effect on July 1, 2013.
"FMCSA stated that their field study results supported the efficacy of the new restart rule,” said ATRI. “Following a detailed evaluation of the field study report, ATRI identified a variety of technical issues related to research design flaws, validity of measurement techniques and interpretations and data conflicts within and across the study.”
ATRI claims Congress required that the field study be “representative of the drivers and motor carriers regulated by the hours of service regulations” but says the study includes, on average, less than 12 days’ worth of data for each of only 106 drivers.
It also says the field study report purports to have measured differences between restarts with one and two nighttime periods, from 1 a.m. to 5 .a.m., but instead measured differences in restarts that range from 34-hours to an unknown/non-limited number of hours off-duty.
Other problems ATRI found with the FMCSA field study include:
- It does not present research to support the limitation of the use of the 34-hour restart to once per 168 hours, or once per week.
- Use of the three-minute Psychomotor Vigilance Test, which measures reaction time to visual stimuli, showed lapses of attention by drivers in both duty cycle groups, but offered no link between the average number of lapses, fatigue and the safe operation of commercial vehicles.
- The two duty cycle groups had lane deviation measurements that differed by 1/10th of a centimeter and the study authors provide no evidence that these findings are relevant or are an indicator of driver fatigue in either of the two groups.
- The difference in sleep obtained by the two duty cycle groups on their restart breaks differed by only six minutes per 24-hour period.
- Average driver scores on the subjective sleepiness scale did not indicate any level of sleepiness.
- The study confirms that drivers in the “two or more nighttime” group are more likely to drive during the day, a time when FMCSA’s own data shows a higher crash risk.
ATRI is the not-for-profit research arm of the American Trucking Associations and describes its report as an “independent evaluation.”
A copy of this report is available from the ATRI website.