AUGUSTA – A rash of fatal accidents has kept state police investigators busy during the height of Maine’s deadliest driving months.

Eighteen people have been killed so far this month in traffic wrecks, state police spokesman Stephen McCausland said late Tuesday afternoon.

“July and August are Maine’s most deadliest months,” McCausland said.

During a three-day period from Saturday through Monday, troopers responded to three double-fatal wrecks: one early Saturday morning in Plymouth, another Saturday night on Route 17 in Roxbury, and a third Monday night in Oxford.

Fatal accidents “are happening all over the state and there doesn’t seem to be any common threads. Speed and alcohol were involved in some,” he added.

Excessive speed was involved in Monday’s Oxford crash, and excessive speed and alcohol were factors in Saturday morning’s wreck. Investigators are still trying to determine to what extent speed and alcohol played in the Roxbury crash.

“Two young men were killed in Plymouth; there was a motorcycle fatality in Augusta Sunday evening; a Mapleton man was killed Sunday night in Castle Hill; an elderly woman was killed in Aroostook Saturday night; there was an ATV crash in York County where alcohol was a factor,” McCausland said.

He also said that including Sunday evening’s motorcycle wreck that killed an elderly Sidney man, there have been four other bike fatalities.

One killed a Lincoln woman Sunday afternoon in Millinocket when a pickup truck collided with the motorcycle on which she was a passenger.

There were two fatalities in Lewiston last Wednesday when two bikers crashed within 30 minutes of each other. And another happened earlier that afternoon when a New Brunswick man’s motorcycle was struck by a moose in Aroostook County.

Drivers, McCausland said, should be very careful in the state during July and August.

“This is the time of the year when the most vehicles are on the roads. People are vacationing now and letting their hair down. People driving during these two months have got to be extra cautious,” McCausland added.