Two severe motorcycle accidents over the Labor Day weekend were the latest in a spate of motorcycle crashes this summer.

Stephen McCausland, spokesman for the Maine Department of Public Safety, said there have been a high number of motorcycle accidents this summer.

“It’s been a bad summer for motorcyclists,” McCausland said Sunday. “It’s been a deadly year.”

Twenty-one people have died from motorcycle crashes this year, compared to 11 for all of 2014, according to state records.

The Maine Bureau of Highway Safety annual reports show motorcycle fatalities ranging from 15 to 24 per year from 2005-12.

While it’s difficult to speculate why motorcycle fatalities have increased, more drivers are on the roads this year. Traffic spiked this summer as tourism rebounded in 2015, according to the Maine Turnpike Authority, including a record-breaking August, with more than 8 million passenger cars on the turnpike.

In both motorcycle accidents this weekend, speed and erratic driving were factors, McCausland said.

Randall Goslin, who was in grave condition Sunday night at Maine Medical Center, was not wearing a helmet when he crashed Saturday evening, according to McCausland.

Goslin, 40, of Farmington, New Hampshire, was thrown after the motorcycle he was operating hit a utility pole on Route 202 in Lebanon near the New Hampshire border. Goslin landed on nearby River Road.

Meanwhile, Alexander Small, 21, of Richmond, died Saturday after the motorcycle he was driving collided with a sport utility vehicle on Interstate 295 in Falmouth. Small was wearing a helmet.

Earlier this summer, a South Portland woman died in a crash in Westbrook and a woman died in Durham after failing to negotiate a curve.

According to the Bureau of Highway Safety, riders who are not wearing a helmet account for about two-thirds to three-quarters of all motorcycle fatalities in a given year.

Paulette Beaudoin, a former state representative from Biddeford who tried for eight years to get a motorcycle helmet law approved in Maine, said it upsets her to see people dying when they could have been protected by head safety gear. Beaudoin’s bills failed in every session through 2013, when she was termed out of office.

“Every time I see the news and someone has died from not wearing a helmet, I feel so awful,” Beaudoin said. “I tried like hell to pass that bill. But nothing I did worked.”

Opponents of motorcycle helmet laws say a requirement to wear helmets infringes on personal freedom. Maine required all motorcycle drivers to wear helmets in the 1960s and 1970s, but the helmet law was repealed in 1977.

However, some motorcycle riders must wear a helmet, including those age 18 and younger, those with learner’s permits and first-year licensees.