A warning from Ontario's police chiefs.
They say drug-impaired driving will likely increase once recreational pot is legal.
And they say they'll need more funding to deal with it.
That funding includes training more officers to detect drug impairment.
Police say that promised federal funding may not go far enough.
OPP Chief Superintendent Chuck Cox says some officers are already trained in how to recognize drug impaired driving.
But he says forces may need more officers who are qualified drug recognition experts and certified to perform standardized field sobriety tests.