AUGUSTA, Maine — Maine State Police said 16 pedestrians have been killed by cars so far in 2015, making it the deadliest year for walkers in at least a decade.

No one can say for sure why getting around on foot has turned deadly for more people, but according to state police, most of the accidents were caused by pedestrian error and a lack of visibility.

Just last week, an 83-year-old man was hit and killed while crossing the street to get his mail in Pittston. The week before that, an 86-year-old was hit crossing Lisbon Street in Lewiston. In August, a 23-year-old girl was killed along a York road, and a 75-year-old in Harpswell while walking her dog.

“We’ve had an exceptional fall, in which people are out and about a lot more often,” said Stephen McCausland, the spokesman for the Department of Public Safety. “Of course, with the time change and season, it gets dark a lot earlier. All of those could be factors.”

State police said some of the victims were also wearing dark clothes and others were in the road when they shouldn’t have been.

Robert Wallace West, 50, a homeless man in Bangor died while crossing Hammond Street in front of Bahaar Pakistani Restaurant at night on May 30.

“Many of the deaths that have occurred have been adults,” said McCausland. “These are all adults and they have just made some poor decisions.”

“We think it is tragic, outrageous, horrible,” said Jim Tasse, assistant director for the Bicycle Coalition of Maine, which also emphasizes pedestrian safety.

He said everyone should keep three things in mind: Be visible by wearing bright or reflective clothing; walk against the traffic, not with it; and when possible, use a sidewalk or crosswalk.

“You know that two-second decision about what color jacket to wear can have a huge impact on your safety,” said Tasse.

While pedestrian and motorcycle deaths are both up, McCausland said highway fatalities overall are running average, about the same as last year.