ORILLIA, Ont. -- Provincial police say traffic fatalities in OPP jurisdiction increased last year, but deaths due to the so-called Big Four causes were down.

Statistics released this week show 299 people were killed in 260 fatal collisions on OPP-patrolled roads last year, compared to 288 in 2014.

But police say while deaths due to alcohol or drugs, inattention, speed, and not wearing a seatbelt declined in 2015, the Big Four still accounted for the majority of the deaths -- 226.

Police also say last year marked the lowest number of alcohol or drug-related deaths in more than 10 years and the fewest of inattention-related road deaths since Ontario introduced distracted driving laws in 2009.

But they also say the number of multiple-death collisions rose in 2015 -- there were four times as many crashes in which three people died and one of the collisions claimed the lives of four people.

Seventy-one people died in collisions involving large commercial transport trucks last year, compared to 66 in 2014, and 2015 had the highest number of transport truck-related road deaths in the last eight years.

Motorcyclists were the only road user class that did not see an increase in fatalities in 2015, however the decrease was minimal, 33 fatalities compared with 32 in 2014.

OPP officers responded to 69,469 road collisions in 2015, compared to 75,644 in 2014, the force said.

"We are encouraged to see lower numbers in all of the Big Four fatality causal factor categories, but we need to see drivers keep this downward trend going," said Deputy Commissioner Brad Blair.

Chief Supt. Chuck Cox noted that the burden of physical and emotional injury on those who survive a fatal road crash is extensive.

"Many require long-term physical and psychological rehabilitation after surviving such a violent, catastrophic and traumatizing ordeal," Cox said.

"For some, the suffering lasts a lifetime."

Police did stress that distracted driving was the cause of more deaths than any other factor for the third consecutive year, contributing to 69 deaths in 2015.

"If you are texting, you are not driving," Commissioner Vince Hawkes said Friday in a release.