FALMOUTH – A teen-ager from Silver Spring, Md., committed suicide when he drove his father’s car in the wrong direction on the Maine Turnpike and slammed head-on into a tractor-trailer, authorities said Tuesday.

Daniel McGivren’s death followed a 12-hour car trip Monday that began after he dropped a friend off at school at about 8 a.m. but skipped classes himself and headed north, police said.

The crash occurred shortly before 8:30 p.m. after McGivren, 16, pulled his car into a median crossover between turnpike Exits 10 and 11, turned off the lights and sped north in the southbound lanes, said Stephen McCausland, spokesman for the Maine Department of Public Safety.

McGivren, a high school junior, died instantly when the car collided with the waste disposal truck, McCausland said.

McGivren’s mother found a suicide note in the boy’s bedroom Monday night after he failed to return home from school, the spokesman said.

“It was clear he was despondent,” said McCausland, declining to reveal the contents of the note.

McGivren made no attempt to move out of the way of the truck or apply his brakes, its driver, Mark Searway, 39, of South Portland, told police. Searway suffered minor leg injuries but refused treatment.

McGivren had no apparent connection to Maine, McCausland said.