Motor vehicle accidents account for 40% of the occupational fatalities in Colorado, according to state-chartered Pinnacol Assurance.

Pinnacol, which covers about 60% of businesses in Colorado, said car crashes have cost employers $173 million in claims over the past five years. In addition to causing an estimated 40% of fatal injuries, the carrier said motor vehicle accidents also cause severe injuries to multiple parts of the body, including the head and neck.

The carrier said its analysis found nearly a quarter of those killed in crashes were ejected from the vehicle, suggesting they might not have been wearing a seat belt. Pinnacol recommends employers consider offering safety training to any workers who drive more than occasionally.

Employers have been improving workplace safety in Colorado, but the persistent threat of car crashes remains a concern, Jim McMillen, Pinnacol Assurance’s director of safety services, said in a statement.

“Defensive driving training should be part of any risk management program in which employees must drive for work, even if they’re not considered professional drivers or are driving their personal vehicles,” McMillen said. “The truth is, most of us could stand to take more driving training, and we should always, under all circumstances, put our smartphones away and wear seat belts.”