Highway Safety:

Selected Cases of Commercial Drivers with Potentially Disqualifying Impairments

GAO-13-13: Published: Nov 30, 2012. Publicly Released: Nov 30, 2012.

Additional Materials:


Cathleen A. Berrick
(202) 512-6722


Office of Public Affairs
(202) 512-4800

What GAO Found

The Federal Motor Carrier Safety Administration (FMCSA), part of the Department of Transportation (DOT), has established a number of key controls designed to prevent commercial driver’s license (CDL) holders from operating commercial vehicles while impaired. First, drivers are required to undergo regular medical exams by a certified medical examiner. Second, employers are responsible for drug testing employees at various points of employment. Third, state and federal roadside-inspection programs are in place to identify impaired drivers and perform other safety checks. If these key controls are operating effectively, they will help identify commercial drivers who are not capable of driving safely. However, GAO’s prior work has found that these controls were vulnerable to abuse or manipulation. The Moving Ahead for Progress in the 21st Century Act, enacted in July 2012, will require additional measures to ensure that disqualified drivers do not operate commercial vehicles, and could help address some of these vulnerabilities. For example, the law requires DOT to implement a national clearinghouse of commercial-driver controlled-substance and alcohol test results by July 2014. DOT has also taken some actions, and now requires CDL holders to provide a copy of their medical certificates to the State licensing agency.

Matching CDL holders with Social Security Administration (SSA) disability files produced 204 commercial drivers who drove a commercial vehicle as recently as 2011 despite having epilepsy, a disqualifying medical condition characterized by sudden seizures and unconsciousness. Thirty-one of these drivers were involved in accidents, demonstrating the threat to public safety posed by medically impaired drivers. GAO also identified 23 cases where state licensing agencies issued or renewed CDLs for drivers after they were, according to SSA records, diagnosed with epilepsy or had drug or alcohol dependence noted, which could also disqualify them from driving under DOT regulations.

However, because DOT did not require state licensing agencies to maintain drivers’ medical certifications at the time of GAO’s review, it is unlikely that states knew of the drivers’ conditions. In fact, they were unable to provide medical certifications for any of the 23 individuals. States are now required to electronically store medical certificates for new and renewing CDL applicants and will be required to electronically maintain this information for all CDL holders by January 2014. Doing so could help prevent ineligible drivers from obtaining or renewing CDLs in the future.

Why GAO Did This Study

Commercial vehicles such as tractor trailers and school buses must be operated by skilled drivers who are mentally and physically capable of performing their jobs safely. Prior GAO work has shown weaknesses in DOT’s oversight of CDLs, such as inadequate medical certifications for commercial drivers, potentially putting the public at risk.

GAO was asked to update its work on impaired commercial drivers. This report describes (1) key controls designed to prevent medically unfit or impaired commercial drivers from operating commercial vehicles and (2) examples of commercial drivers with potentially disqualifying impairments related to epilepsy, drugs, or alcohol.

To identify key controls, GAO reviewed FMCSA policies and regulations, and interviewed officials. Cases were identified on the basis of FMCSA roadside-inspection data, DOT’s Commercial Driver License Information System (CDLIS), a national database of all commercial drivers, and SSA disability insurance files. From this analysis, GAO identified commercial drivers who were driving with an epilepsy diagnosis. GAO also randomly selected 100 individuals to determine whether the driver was receiving SSA disability benefits when the state issued or renewed the driver’s CDL. These cases cannot be generalized beyond those presented.

GAO provided a draft of this report to SSA and DOT. SSA did not have any comments. DOT provided technical comments, which have been addressed in the report, as appropriate.

For more information, contact Cathleen A. Berrick at (202) 512-6722 or BerrickC@gao.gov.

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