Four people were killed in traffic accidents in Maine over the weekend.

On Sunday evening in the York County town of Acton, Dakota Thomas, 22, of Sanford lost control of his motorcycle on Route 109, drove across a lawn, struck a dip in the ground, and was ejected from the motorcycle, landing in the woods, Sheriff William L. King Jr. said.

Thomas, who was riding with two other bikers and was wearing a helmet, was pronounced dead at the scene.

Excessive speed is believed to have been a factor in the crash, King said.

A Greene woman was killed early Saturday when the car she was driving crashed head-on into a tree a short distance from her home, according to Maine State Police.

Amanda “Mandi” Rines, 25, was dead when police arrived around 1 a.m. to find the car off the road on Allen Pond Road in Greene, Stephen McCausland, spokesman for the Maine Department of Public Safety, said Monday.

Rines was not wearing a seat belt, and police believe alcohol was the primary factor in the crash, he said.

State police said Travis Lowberg, 24, of Raymond was killed around 3 a.m. Saturday when his car crossed the centerline and struck a tractor-trailer on Route 202 in Hollis.

Lowberg was pronounced dead at the scene. The tractor-trailer caught fire but the driver climbed through a passenger side window to reach safety.

Adam Kimball, 43, of Lyman was killed around 1 p.m. Saturday in a motorcycle crash on Route 5 in Dayton.

State police said Kimball lost control of his motorcycle. He was not wearing a helmet and was thrown from the motorcycle, which hit a tree and landed next to him, police said. Excessive speed may have been a factor in the crash.