Police are out in full force this Labour Day long weekend, cracking down on aggressive drivers on Ontario's roadways and taking a zero-tolerance approach to noise and disorder in Ottawa's downtown core.

"We're looking to set a tone, set a standard for acceptable behaviour in the downtown core, particularly in the entertainment district," said Ottawa police Staff Sgt. Uday Jaswal.

Police said while they encourage people to enjoy Ottawa's nightlife, they want people to take accountability for their actions.

On the province's roadways, police are watching out for speeding, drinking and driving, seatbelts and proper protocol when passing emergency vehicles.

An OPP cruiser was struck Friday morning while it was parked on Highway 400 northbound. Police said the officer was dealing with someone stopped for an infraction when a motorist struck the cruiser from behind.

"That's why we have this 'move-over' law that came in 2003. You're supposed to move over a lane to avoid such things like that," OPP Sgt. Dave Woodford told CTV Toronto.

"We're out there doing a job, and you don't have to slam on your brakes. Just keep driving and go by the scene."

Last year, four fatalities were recorded in four separate alcohol-related crashes on Ontario's roadways. Provincial police also laid more than 1,700 charges in eastern Ontario.

Those charges included 963 drivers caught speeding, 26 racing charges, 195 seatbelt infractions, 71 marine offences, 71 Liquor Act infractions and 22 drug offences.