WASHINGTON, D.C. — The gloves have come off in the dispute over US truck driver hours-of-service, with the American Trucking Associations (ATA) accusing the Federal Motor Carrier Administration of manipulating the numbers.

According to ATA, the FMCSA has misapplied its own crash numbers to suggest driver fatigue is a factor in more crashes than it actually is.

“Since the current HOS rules were introduced in 2003, the trucking industry has achieved a continually improving safety record, reaching the lowest fatality and injury rate levels in recorded history,” said ATA president Bill Graves “It is troubling that this complex, restrictive set of proposed rules is founded on what appears to be incorrect analysis and inflated math.”

The ATA contends the FMCSA has inflated its estimation of fatigue-related crashes in two ways. First, in its large truck crash causation study, ATA says FMCSA assessed twice the value to a single-vehicle truck crash compared to multi-vehicle crashes. The association points out single-vehicle truck accidents are more likely to be fatigue-related, but giving them twice the weight of multi-vehicle crashes creates the perception that fatigue is a factor in more truck crashes than is the reality, the ATA says.

Secondly, ATA says the FMCSA chalks up every crash where fatigue is an “associated factor” as a fatigue-related crash – a tactic that ATA argues is contrary to prior research methods and contradicts the FMCSA’s own contention that “No judgment is made as to whether any factor is related to the particular crash, just whether it was present.”

FMCSA made that statement in a report to Congress on its Large Truck Crash Causation Study in 2006.

As a result of the alleged “data manipulations,” ATA says the FMCSA has nearly doubled its calculation of truck-involved crashes that are caused by fatigue. In past rulemakings, the ATA says, the FMCSA stated fatigue was a causal factor in 7% of truck crashes. It is now claiming fatigue is a factor in 13% of truck crashes.

The ATA says it will be calling the FMCSA out on further “creative” accounting in other aspects of its argument, which seems geared towards reducing daily driving time.