Ontario Provincial Police ticketed a 47-year-old woman for driving 40 km/h on Highway 401 near Mallorytown, Ont., Wednesday evening.

Leeds County OPP received calls just after 8 p.m. that an eastbound vehicle was driving slowly in the fast lane with high beams blazing.

They located the car and tried to get the driver to pull over, but to no avail. 

"After some precarious attempts, officers had to make a tandem stop with a cruiser in the front and rear of the vehicle to safely assist movement off the highway," they said in a Thursday news release. 

The driver believed the speed limit on the 401 was 50 km/h, OPP said. In reality, it's 100 km/h.

Officers ticketed her for unnecessarily slow driving, failing to obey signs and failing to provide proof of insurance. 

Police continue to investigate.