Police on Friday still were uncertain why a man who was killed on Interstate 95 Thursday night was driving the wrong way in the southbound lane.

John Polchies Jr., 28, most recently of Hancock Street in Bangor, was killed instantly when his car collided head-on with a tractor-trailer truck underneath the Hogan Road overpass in Bangor.

State Trooper Barry Curtis said several witnesses contacted him Friday and claimed to have seen Polchies’ vehicle headed the wrong way before the accident occurred.

Curtis said that according to witnesses, Polchies was headed in the right direction and then turned around and drove directly into oncoming traffic. Curtis said it appeared that Polchies turned around at least two or three times and blinked his headlights on and off as he continued to drive north in the southbound lane.

A test was performed to determine Polchies’ blood-alcohol level but results were unavailable on Friday.

Curtis said Polchies’ license was under suspension when the accident occurred. He recently had been charged with operating a motor vehicle while under the influence of intoxicating liquor and that case was scheduled to go to court in April, Curtis said.

Curtis said the accident was still under investigation.

The driver of the tractor-trailer truck, Simon Harvey, 40, of Orlando, Fla., was uninjured.

Curtis said he had not determined how fast either vehicle was traveling.

“The truck driver said he was going between 55 and 60 miles per hour. He said that when he noticed the car coming toward him it was really moving,” Curtis said.

Harvey tried to avoid the accident by swerving to the left. He was passing another car at the time and was unable to get back into the right lane, Curtis said.

“He did his best to avoid it but there was no place for him to go,” said Curtis.

Polchies was originally from Bar Harbor.