BANGOR, Maine — Initial estimates that 75 vehicles were involved in the massive pileup early on Feb. 25 on Interstate 95 in central Maine were well below the actual number, according to police who investigated what is believed to be Maine’s most extensive traffic accident.

There were 102 vehicles involved in collisions and another 40 or so that either slid off the road or spun out to avoid crashing, according to a summary of investigators’ findings released Wednesday. A total of 32 of the 149 people in the vehicles had reportable injuries, according to the summary prepared by Lt. Sean Hashey, Maine State Police Troop E commander. Only one vehicle occupant was not wearing a seat belt or restrained by other safety devices such as child car seats.

No criminal charges are expected to be filed in connection with the crash, according to the summary.

“We looked at: Was there a crime that led to this,” Hashey said Wednesday. “[For example], was someone driving drunk. We determined there was no crime. There was a series of bad decisions and some traffic infractions.”

Some of the drivers involved could have been charged with imprudent speed, Hashey said, adding that investigators decided not to issue tickets in hopes the drivers learned from the experience and will slow down next time.

“We focused on how can we prevent this from happening again,” the lieutenant said. “I think it stuck with people.”

The initial call for help was made from Carmel at 7:32 a.m. amid falling snow.

“The first confirmed event involved an SUV that was traveling northbound when the driver lost control on the slippery roadway,” according to Hashey’s summary. “The vehicle spun 360 degrees and struck the right-hand guardrail, which caused minor, nonreportable damage to the driver’s side rear of the SUV.”

The SUV came to rest in the travel lane at about mile marker 172, blocking passage on the right and starting a chain reaction that led to crashes stretching back for nearly four miles.

“While the SUV was spinning, a line of three vehicles were approaching,” Hashey said. “The first vehicle moved into the passing lane and avoided the SUV. The second vehicle quickly moved into the passing lane to avoid the SUV and clipped the front of the third vehicle that was already in the passing lane. The operators of those two vehicles were able to safely pull to the breakdown lane and make the first 911 call to police.”

A few others reported fishtailing and crashing into snowbanks, and then came a tractor-trailer.

“The driver of an unloaded tractor and trailer log truck began to jackknife as he attempted to move around the SUV,” the summary states. “The driver of the log truck purposely drove off of the roadway to avoid striking the SUV. The truck came to rest in the ditch on the right side of the highway and was undamaged. A pickup truck driver also saw the SUV in the travel lane and attempted to move into the passing lane. The truck driver became involved in a three-vehicle crash.”

Multiple other crashes occurred, with the initial primary blockage and pileup involving 39 vehicles, including a school bus, two tractor-trailers, a flatbed wrecker, a commercial truck, 34 passenger vehicles, most crushed into a pile together. Included among the reported injuries was a woman who had a heart attack.

The report states the entire multivehicle crash was caused by a combination of factors and simultaneous events including operators driving too fast for conditions, operators following too closely, slippery road conditions, weather and poor visibility.

Most drivers in the area were traveling at least 10 mph over the posted 45-mph speed limit around the time of the accident, according to data collected by the Maine Department of Transportation released last week from the flashing hazardous-weather speed limit signs along the federal highway.

Additional factors include the downhill slope of the roadway with the fresh snow, a long-sweeping right-hand curve and the funneling effect of the guardrails located on both sides of the roadway, the summary states.

“It should be noted that not every vehicle involved in this incident had driver’s actions that [contributed] to the event; several vehicles were able to safely avoid the collisions in front of them only to be struck from behind,” Hashey said.

Seventeen injured people were taken by ambulance to Bangor hospitals, four others went to walk-in care, and 19 others — some who had reportable injuries — were treated at the scene, according to the summary.

The partnership of people assisting each other — responders, some on-duty and some off-duty, and those involved in the accident — helped to make the mass confusion a workable situation, Hashey said.

“Motorists provided blankets, cellphones and warm vehicles for several of those that were involved in accidents,” the summary states. “RSU 19 provided a warming bus off-site for people to gather while they waited for family or friends to arrive.

“Fire and EMS personnel, law enforcement, regional communications centers, wrecker companies, hospitals and Maine DOT worked extremely well together to rescue the injured, stabilize the scene, reroute traffic, conduct [a] preliminary investigation and eventually return the interstate to full operation in less than 5 hours,” Hashey said.