The Federal Motor Carrier Safety Administration named three truck drivers as imminent hazards for separate crashes in which people were either killed or seriously injured.

Scotty Arnst, a driver for Arkansas carrier Dollar Trucking, struck and killed two people changing a tire on the shoulder of Arkansas Highway 7, the agency said.

In its investigation of the September 22 crash, the agency learned that Arnst had worked for three separate carriers in the previous nine months and had not told any of them that he’d been involved in previous crashes and had been fired for high-risk driving.

Arnst also had not disclosed that he had disqualifying medical conditions, and had submitted outdated medical examiner certificates, the agency said.

The second driver, Stewart Snededker of the Illinois carrier Paris Transport, hit a Tennessee Highway Patrol cruiser parked on the side of I-75 with its lights flashing, seriously injuring the trooper. This was on June 23.

Snedeker fled in his truck and was apprehended 10 miles away. He was charged with driving under the influence, among other offenses.

Investigators later learned that Snedeker had potentially disqualifying medical conditions and had falsified his medical history.

The third driver, Tracy Ferrell of Fleet Quest Inc. in Michigan, drove into the back of a passenger car stopped in traffic on U.S. Highway 23 in Ohio, killing the driver.

The investigation of the September 11 crash found that Ferrell had exceeded hours-of-service limits and repeatedly falsified his on-duty records during the five weeks before the crash.

Each of the three has been placed out of service. So far this year the agency has made a total of 10 such declarations.