This is somewhat a discussion of roads, but I believe if you read the article again they simply say commuter. Would that not then mean it includes all transit commuters too?
I'd argue that those numbers for Vancouver and Burnaby reduce considerably from a road standpoint when you assume a large number of those commuters actually take SkyTrain not their cars.
Or am I missing the sentence that says "this is for car commuters only?"
It does lend itself to the notion that the mayors of Burnaby and Vancouver being up and arms about more road infrastructure in the suburbs were wrong in their saying it would "only being more cars to our city." since clearly most people commuting South of Fraser, stay in South of Fraser. Heck most Surrey commuters stay in Surrey itself.