BAILEYVILLE — Dense fog was one of the factors that caused an early morning accident Wednesday between a car and tractor-trailer that left one man critically injured.

John Steadman, 71, of Calais suffered serious head injuries. He was taken by ambulance to Calais Regional Hospital and was transferred to Eastern Maine Medical Center in Bangor. Hospital officials listed Steadman in critical condition late Wednesday afternoon. At around 7 a.m., Steadman, who owns Steadman’s Service Center on Route 1, was traveling north in his 1983 Ford LTD toward Baileyville on his way to work.

At the same time, Eurie MacLean, 59, of Hunter River, Prince Edward Island, who was driving a 1995 Freightliner tractor-trailer, was preparing to leave the parking lot at the Irving Big Stop at the junction of Routes 1 and 9, said Chief Phil Harriman Wednesday. MacLean was planning to go south into Calais with a load of blueberries for Nova Scotia.

Harriman said it was very foggy at the time, and before MacLean pulled onto Route 1, he checked for traffic on his left and right. He told police that he saw cars in the distance with their headlights on. He pulled his rig out onto the road, and Steadman, who did not have his lights on, collided with the rear end of the trailer. The car’s roof was crushed when it went under the trailer.

The Calais Fire Department’s rescue team was called to the scene to extricate Steadman.

The chief said that although dense fog was a factor in the accident, police were continuing their investigation. He said that in addition to the Calais Fire Department, local police were assisted by the Baileyville Ambulance Corp. and Maine State Police Trooper Tim McCadden.

McCadden said MacLean was summoned for operating a truck in violation of the 70-hour rule. The trooper said that rule prohibits a driver from working more than 70 hours during an eight-day work period. He said that although MacLean had been summoned for that violation, he did not wish to suggest that the driver was tired or had been driving all night.