Cpl. Shawn Pollard, head of the RCMP's traffic unit in Yukon, said fatigue is a serious problem on Yukon highways because of the long distances and open roads. (CBC)

A Yukon RCMP officer got a big surprise during a highway patrol last weekend when a driver passed him at a speed of 170 km/h.

The officer was driving on the Alaska Highway near Marsh Lake in a fully marked police car with a light bar on top when the driver overtook him at a high speed.

Cpl. Shawn Pollard, who heads Yukon’s traffic unit, says the driver didn't even realize it was a police car.

"This vehicle came up behind him and pulled out and passed and when the lady was stopped, she indicated that she didn't even see the police car, didn't recognize it because she was driving too fast," Pollard said.

He said the woman also mentioned she was sleepy.

Pollard said that's not unusual. Fatigue is an issue on Yukon highways because of the long distances and open roads.

And it kills people.

Pollard said during a recent highway checkstop in Watson Lake, Yukon, some travellers he spoke to mentioned they were tired. He advised them to stop and rest. About a half hour later, he heard they’d had an accident farther along the highway.

RCMP in the Yukon are joining counterparts across the country to mark Safe Driving Week.

It coincides with the start of summer travelling on the May long weekend.