Noting an increase in crashes, the B.C. government is lowering speed limits on highways around the province – including three on Vancouver Island.

The province says it's lowering speed limits by 10 kilometres on 15 stretches of highway in B.C. four years after they were increased.

That increase in speed limits resulted in a higher number of crashes on certain corridors, according to a study conducted by B.C.'s transportation ministry.

Based on the results of the study, the province announced Tuesday it would roll back the speed limit on the routes that have seen increases in crashes.

On Vancouver Island, the stretch of the Trans-Canada Highway from Cowichan Bay to Nanaimo will be rolled back to 80 kilometres an hour, from 90.

A stretch of Highway 19 from Parksville to Campbell River will drop from 120 km/h to 110 km/h.

A separate section of Highway 19, from Sayward to Bloedel, will have its limit lowered to 90 km/h, down from 100 km/h.

All of the speed limit reductions are going into effect immediately, and the ministry says 339 needed sign changes will likely be complete by the end of the week.

"We know people want to get where they're going quickly. Our job is to help make sure they also get there safely," transportation minister Claire Trevena said in a statement. "Since the former government raised speed limits in 2014, serious crashes have been on the rise. By rolling back speed limits slightly, our goal is to reduce accidents, keep roads open and protect the lives of British Columbians."

In total, 660 kilometres of B.C. highways will have lowered speed limits.

Provincial health officer Dr. Bonnie Henry says research shows reducing speed lowers the number of crashes and severity of injuries.

The BC Trucking Association has also thrown its support behind the move, saying it will not only make roads safer but help increase fuel efficiency.