The U.S. Government Accountability Office reports that, nationwide, more than a half-million drivers of commercial vehicles such as trucks and buses have medical problems that could qualify them as disabled. While the GAO report notes that disabilities do not necessarily make a commercial driver unfit for the road, highway safety advocates say these medical problems could raise the risk for everyone. VOA's Jeffrey Young reports.

U.S. highways are jammed with big trucks and buses carrying goods and people across the nation.  Federal and state regulations help ensure that commercial vehicles are in good shape, and driven by capable people.  

But a new study by the U.S. Government Accountability Office suggests to some that there may be a hidden problem.  The report says some drivers have medical problems that could contribute to crashes and fatalities.

The U.S. Department of Transportation says in 2006 trucks and buses were involved in crashes that killed 5,300 people.  

In May 1999, a bus crash near New Orleans killed 22 people. The driver had serious heart and kidney conditions.  But he still held a commercial driver's license.

Up to 12 million people in the U.S. hold these licenses; 563,000 of them, according to the GAO, have qualified for health-related disability benefits. Among that group, the report says more than one thousand have vision and other problems serious enough to deny them a commercial license.

While DOT says only three percent of the crashes in 2006 involved commercial drivers with medical problems, highway safety is a serious concern for the advocacy group Public Citizen's Joan Claybrook.  

"We think these vehicles are essentially rolling time bombs because they're definitely going to kill people if they crash," she said.

The trucking industry's lobbying group, the American Trucking Association, says the medical issue is being blown out of proportion. 

ATA's David Osiecki says, "To paint the industry and truck drivers as having a significant problem in the medical arena is not fair or appropriate."

The trucking industry spokesman told VOA that among those with medical disabilities are those who have problems unrelated to driving, such as problems with walking.

Later this week, the House [of Representatives] Transportation and Infrastructure Committee will hold hearings on ways to better monitor who is behind the wheel of the nation's trucks and buses, and how to get unfit drivers off the roads.