The long-simmering controversy over how medical examiners decide when they should send truck drivers at risk for obstructive sleep apnea to undergo costly lab sleep studies is heating up again.

Researchers believe many truck drivers on U.S. highways have untreated sleep apnea, which remains a public safety danger and a serious driver health issue.

A medical advisory board to the Federal Motor Carrier Safety Administration has recommended that medical examiners be permitted to offer truck drivers alternative treatment options to sleep apnea machines that are subject to a massive recall.

Members of the Federal Motor Carrier Safety Administration’s medical review board are due to address uncertainties connected to a voluntary recall of some continuous positive air pressure machines, warning that truck drivers using them face potential health risks.

The Federal Motor Carrier Safety Administration is expanding access to information about obstructive sleep apnea for medical professionals who conduct medical examinations for truck drivers.

A new obstructive sleep apnea study of 20,000 drivers using a more comprehensive screening evaluation method estimated that nearly 49% of commercial motor vehicle drivers could be at risk for obstructive sleep apnea, a condition that can cause sleepiness while driving.

A National Transportation Safety Board investigation concluded that lack of a “robust medical certification evaluation process” on the federal level to identify and treat commercial drivers at high risk for obstructive sleep apnea was one of three safety issues that contributed to a fatal, multivehicle heavy truck-involved crash in 2018.

The determination by federal investigators that two high-profile train collisions in New York and New Jersey were the result of undiagnosed sleep apnea prompted a member of the Senate Commerce Committee to rebuke the Trump administration’s withdrawal of a potential new policy on the sleep disorder.

Just months after U.S. rail and highway regulators said they were withdrawing plans to screen truckers and engineers for a dangerous sleep disorder, accident investigators believe that it contributed to two New York-area transit crashes.