I live in BC near a highway intersection and in my experience they seem to do what you suggest.
I approach from my street and if the highway is empty, almost instant green. Otherwise I have to wait some time until the road clears. During peak hours when the road doesn’t clear, it just seems to go green after a fixed time.
I approach from my street and if the highway is empty, almost instant green. Otherwise I have to wait some time until the road clears. During peak hours when the road doesn’t clear, it just seems to go green after a fixed time.