A Chester, Maine, man died Monday evening as a result of injuries sustained in a motorcycle accident on I-93 in Thornton.

According to New Hampshire State Police — Troop F, Roy Voisine, 54, was riding a 1993 Honda motorcycle south on the highway when he lost control of the bike and went off the right side of the highway, impacting a highway sign.

Voisine suffered significant injuries and was pronounced dead at the scene, Troop F said.

“Although all factors are still being considered, it appears that speed and alcohol are both contributing factors in this collision as a witness reported seeing the motorcycle operating erratically and traveling at a speed above the posted speed limit prior the crash,” state police said.

Anyone who witnessed the crash is asked to call Trooper Michael Bruno at 603-223-3796 or email michael.bruno@dos.nh.gov .

Troop F was assisted by Campton Police Department, Campton-Thornton Fire Rescue, Grafton County Attorney’s Office and the Office of the State Medical Examiner.