UPDATED -- The Federal Motor Carrier Safety Administration claims a new study confirms its Compliance, Safety, Accountability enforcement program is more effective at identifying commercial bus and truck companies of all sizes for targeted enforcement than the system it replaced.

The study was conducted by the Volpe Center, the research arm of the U.S. Transportation Department. It comes after a separate study was released earlier this week by the Government Accountability Office, which found problems with CSA and its principal component, the Safety Measurement System. Both were launched nationally in 2010 to identify and prioritize motor carriers that pose the highest threat to public safety for enforcement interventions.

Researchers analyzed the association between historical carrier data and future crash involvement by taking two years of pre-SMS safety data, known as SafeStat, for a subset of carriers, running it through the system’s algorithm, and then following those companies’ crash records for 18 months, according to the agency.

“Results show that the companies the SMS would have identified for interventions, such as roadside inspections, warning letters and on-site investigations, had a future crash rate of more than double the national average,” FMCSA said. “In addition, 79% of the carriers that SMS would have ranked as high risk in at least one of the seven safety categories it monitors, had higher future crash rates compared to those it would not have identified”

The American Trucking Associations criticized the FMCSA for “issuing an overly rosy self-assessment” of CSA following the GAO report.

ATA President and CEO Bill Graves said, "Just because CSA is an improvement over previous programs does not make it a 'good' program for assessing the safety performance of individual carriers as the Government Accountability Office demonstrated earlier this week."

ATA noted the FMCSA assessment mirrored GAO's findings with respect to the limited amount of data available on smaller carriers, and despite the fact that fleets with 5 or fewer trucks represented 75% of the carriers in the study, the authors acknowledged that there is very little available safety information on these carriers to "make a meaningful safety assessment."

“Perhaps most importantly, the report acknowledged that while the aggregated CSA data may be helpful for enforcement purposes, it can be misleading with respect to assessing the performance of individual carriers,” said ATA. “In fact, 93% of the carriers monitored in the study had no crashes."

"The report demonstrated that if you compare the performance of the relatively few fleets that have scores in the system against other carriers, including those with minimal data in the system or no scores, you can paint a positive picture of the program," said Graves.

ATA said its call was echoed by researchers FMCSA had contracted with to peer review the study who raised concerns about CSA and the agency's assessment of it.

"ATA continues to support FMCSA's efforts to rid our nation's highways of unsafe carriers, but the concerns independent researchers, the GAO and ATA have raised show that while CSA may be a modestly better tool for enforcement prioritization, it can and must be improved," Graves said.

The full report from the Volpe Center is available from the FMCSA website.

Watch video of ATA's Rob Abbott talking about the group's objections to this study:

Update adds ATA reaction.