The research used to confirm the benefits of last summer’s changes in truck drivers’ hours-of-service rule has significant problems, according to an analysis published Tuesday. The government agency that sponsored the study, however, says the revised HOS rule works as intended.
The American Transportation Research Institute says it has identified a variety of technical issues related to research design flaws, validity of measurement techniques and interpretations and data conflicts within and across the Federal Motor Carrier Safety Administration’s field study, released in January.
FMCSA collected fatigue measurements from 106 truck drivers during two duty cycles that included two restart breaks. FMCSA contends the results support the efficacy of the restart rule that went into effect July 1, 2013.
The trucking industry and some members of Congress immediately criticized the report. Congress also has recently asked the the Government Accountability Office to evaluate the studies done by FMCSA to create and back the rule.
The Technical Memorandum by ATRI, the research arm of the American Trucking Associations, documents the following issues with FMCSA’s study:
- The field study report purports to have measured differences between restarts with one and two nighttime periods (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.
- MAP-21 required that the field study be “representative of the drivers and motor carriers regulated by the hours of service regulations” but the study includes, on average, less than 12 days’ worth of data for each of only 106 drivers.
- The FMCSA field study does not present research to support the limitation of the use of the 34-hour restart to once per week (168 hours).
- Use of the 3-minute Psychomotor Vigilance Test 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 have a nexus to 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.
“FMCSA has heard loud and clear from carriers and drivers that the new rules are not advancing safety and are creating additional stress and fatigue on the part of truck drivers,” says Steve Rush, president of Carbon Express Inc. in Wharton, N.J. “ATRI’s analysis raises enough questions about FMCSA’s own study that should compel a comprehensive review of the entire rule.”
The trucking regulator continues to defend both the study and the rule.
“ATRI’s report is an attempt to cloud the fact that the updated hours-of-service rule is working to ensure that truck drivers who work extreme schedules of up to 70 hours a week are getting the recuperation time they need before getting back behind the wheel,” says an FMCSA statement. “A well-rested commercial driver is a safer driver.”
The agency notes that the third-party analysis is “one of the largest real-world studies ever conducted with commercial drivers” and found that drivers who began their work week following a 34-hour restart break with just one nighttime period of rest, as compared to two:
- Exhibited more lapses of attention, especially at night;
- Reported greater sleepiness, especially toward the end of their duty periods; and
- Showed increased lane deviation (i.e., more variability in lateral lane position) in the morning, afternoon and at night.
A copy of the ATRI report is available here. ATRI is also looking for input from truck operators on the impacts of the current hours-of-service rule and about detention time for two separate studies it’s working on.