New study of hair testing methods to detect drug use by truck drivers may push DOT acceptance.  -  Photo: J.B. Hunt

New study of hair testing methods to detect drug use by truck drivers may push DOT acceptance.

Photo: J.B. Hunt

Urinalysis is the primary, federally accepted method for administering mandated pre-employment drug tests. Meantime, the Alliance for Driver Safety & Security (also known as the Trucking Alliance) has advocated steadfastly for eight years that hair testing of truck drivers is reliable and more accurate “due to its longer look-back period to identify regular drug use.” That’s why member carriers of the alliance supplement Department of Transportation urine testing by requiring truck drivers to also pass a hair drug test.

The Trucking Alliance holds that hair testing is “scientific, reliable, and accurate; that 13 states recognize hair testing in statute for legal purposes, and that if [use of hair tests is] granted, the companies will continue to require both the DOT urinalysis and an accredited hair test. Additionally, Congress has twice directed the Secretary of Transportation to allow hair testing of commercial truck drivers.”

Study Ranks Hair and Urine Testing

To further build its case for hair testing, the trucking safety lobby on October 11 released results of research it conducted on the effectiveness of hair versus urine tests. The study examined differences between hair and urine drug test results by sampling 172,632 pre-employment hair and urine drug screens that were administered in 2021.

Study data was independently provided by these seven carrier members of the Trucking Alliance: J.B. Hunt Transport, Knight-Swift Transportation, Schneider, Maverick USA, KLLM/FFE Transportation Services, US Xpress, and Cargo Transporters.

The Study Methodology

In 2021, 88,021 licensed truck drivers applied for jobs at the seven alliance member trucking companies listed above. The drivers were asked to take two pre-employment drug tests: the DOT-required urinalysis and a hair drug test requested by the carriers.

Per a summary of the results, the Trucking Alliance determined, “Hair testing is a more effective method to detect the regular use of hard drugs and drug users than the DOT urinalysis.”

Furthermore, the carrier group commented, “If participating carriers did not use hair testing, they likely would have hired 3,959 drivers that failed hair tests. It is likely these individuals are now driving for another carrier, given hair testing results cannot be submitted to the drug and alcohol clearinghouse.”

“Eleven times more truck drivers fail a hair test for illegal drugs than the DOT-required urine test,” said Lane Kidd, managing director of the Trucking Alliance. "That equals thousands of truck drivers. And DOT doesn't know their names.”

"Hair tests uncovered 11 times more drug users than urinalysis, but the marked difference in positive cocaine, amphetamine/methamphetamine, and opioid tests is most troubling," observed Dr. Doug Voss, of the University of Central Arkansas, who conducted the survey. "These results underscore the inability of urinalysis alone to remove hard drug users from the truck driver population."

Crunching the Comparisons Between Tests

The Trucking Alliance pointed to these key study findings:

  • 4,362 driver applicants failed hair tests whereas 403 failed urine tests.
  • Hair testing resulted in an eleven times higher (5.16%/0.46%) overall positivity rate.
  • Hair testing more frequently detected every drug class and better detected hard drugs, such as cocaine, amphetamines/methamphetamines, and opioids.

Based on the number of positive tests contained, the top four drug classes and the substantial differences in those results (in descending order) were:


  • Hair: 1994
  • Urine: 319


  • Hair: 1480
  • Urine: 38


  • Hair:692
  • Urine: 38


  • Hair: 549
  • Urine: 22

According to the Trucking Alliance, the survey suggests that truck drivers are using illegal drugs in dramatically higher numbers than is reported by DOT.  

The survey suggests truck drivers are using illegal drugs in dramatically higher numbers than is reported by DOT.  

The 403 drivers found to have illegal drugs in their system were disqualified for employment and the carriers submitted their names to the DOT Drug and Alcohol Clearinghouse. They must now complete a rehabilitation program before returning to work.

As for the 4,362 truck drivers who were detected for having a regular pattern of illegal drug use, especially for hard drugs like cocaine and heroin, they were disqualified for employment. However, as the clearinghouse doesn't accept hair test results, the Alliance remarked that, “Those drivers went undiscovered, likely found truck driving jobs elsewhere, and resumed their illegal drug habit.”

On the List of Actual Knowledge

The Trucking Alliance has formally requested that the Federal Motor Carrier Safety Administration include positive hair tests on the agency's list of "actual knowledge" of a truck driver's drug use. If granted, these positive hair test results will be submitted to the clearinghouse, making the names of those drivers known to other employers.

The Trucking Alliance’s Kidd said that the DOT had “cast doubt that it would approve the [hair testing] application, but the agency may now take a closer look. The significance of this survey is too big for the Secretary of Transportation to ignore. Most truck drivers don't use drugs, but thousands of illegal drug users are gaming the system and driving large commercial trucks in violation of federal law."

Kidd told HDT that, “The Trucking Alliance secured sponsors and lobbied for adding hair testing as part of the FAST Act highway bill in 2015. DOT has been dragging its feet ever since.”

About the author
David Cullen

David Cullen

[Former] Business/Washington Contributing Editor

David Cullen comments on the positive and negative factors impacting trucking – from the latest government regulations and policy initiatives coming out of Washington DC to the array of business and societal pressures that also determine what truck-fleet managers must do to ensure their operations keep on driving ahead.

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