The crash in Virginia more than a year ago between a train loaded with GOP lawmakers, headed for a getaway retreat, and a trash truck that had ignored the barriers at a railroad crossing was recounted this week by the National Transportation Safety Board.

The NTSB’s conclusion — released Tuesday in advance of the final report — was that the trash truck driver showed poor judgment in circumventing the barriers because he had ingested a mix of marijuana and a prescription drug used to treat pain, seizures and anxiety.

The NTSB said the chartered Amtrak train — two locomotives, a pair of cafe cars and six passenger cars — had departed Washington’s Union Station earlier on the morning of Jan. 31, 2018, with dozens of Republican members of Congress and many of their family members on board. Among them was then-House Speaker Paul D. Ryan (R-Wis.).

One of the three people in the cab of the trash truck was killed; the train engineer had slammed on his emergency brakes but still plowed into the truck at about 35 mph. Another truck passenger was seriously injured, while the 30-year-old driver suffered minor injuries. Four train crew members and three passengers also were injured.

The train was beginning to round a sweeping bend to the left that may have obscured the truck, owned by Time Disposal, from view of the approaching train, according to the NTSB account. Railroad-crossing barriers had dropped into place to prevent vehicles from traversing the tracks.

The train’s engineer sounded its horn at a private grade crossing about 1,000 feet before the Lanetown Road crossing near Crozet, Va. The engineer, the NTSB said, “saw the warning lights flashing [at Lanetown] and the refuse truck drive around the lowered gate arms, but he believed the truck had sufficient time to clear the tracks.”

But for reasons not known to the NTSB, the trash truck stopped on the tracks. The engineer began emergency braking.

The engineer’s observations were supported by a camera on the train that looked out on the tracks. The video showed that:

• The trash truck was visible as the train entered the curve about 1,000 feet away from it.

• The warning lights at the Lanetown crossing were visible and flashing.

• Three seconds before the impact, the gate arms of the crossing are visible and in the down position, but the truck has stopped.

“About 3 seconds after the engineer engaged the emergency brake,” the NTSB report said, “the train struck the left rear side of the refuse truck. The truck rotated counterclockwise, collided with a railroad signal bungalow and a mailbox structure.”

The impact split the truck’s cab from its hopper, spewing a load of trash beside the tracks. The front axle of the lead locomotive derailed, but the train remained upright.

The three people in the cab were not wearing seat belts, and both passengers were thrown from the truck. The passenger in the center seat position died, while the passenger closest to the door was seriously injured. County police identified the dead man as Christopher Foley, 28, of Louisa County.

Some of the GOP lawmakers, including several doctors, climbed off the train and attempted to help those who were injured. Only one member of Congress — then-Rep. Jason Lewis (R-Minn.) — was hospitalized. He was treated for minor injuries and released. The injured Amtrak employees included three in the lead locomotive and one in a cafe car.

Lawmakers aboard the train said they felt a sharp jolt and then a “hard impact” that “threw everybody up in the air a little.”

The crash was “loud and surprising,” said Rep. Thomas ­Massie (R-Ky.). “We saw debris go by the left side of the train. The part of the truck we [could] see was decimated. Very relieved when the train came to a stop and [was] still on the tracks.”

The GOP lawmakers were bound for an annual retreat at the Greenbrier, a resort in White Sulphur Springs, W.Va.