The 'article in front of roads' bit definitely seems to be a west coast thing.
What is generally interesting about this topic is how different everyone is, even within local dialect. You'll notice that a lot of those maps have broad, lightly colored areas, which really don't mean imply some of the meanings that article is trying to put on them. Half the country in faded blue and half in faded red doesn't indicate some giant schism...just that there are general differences, with one region having more that half with one pronunciation (or term), and another region with more than half using the 'opposite.'
It's much easier peg terms like the classic pop/soda/coke. But a lot of pronunciations have 60/40 splits, at most. People tend to go with what they feel sounds right, coupled with what's around them...but if they're around both, it's pretty up in the air.
http://spark-1590165977.us-west-2.elb.amazonaws.com/jkatz/SurveyMaps/
That adds a lot of depth by letting you see the results for your own area. In my case (Tennessee), there is a heavy mix in the middle of the state. It's not very concrete until you move out into the hills. Example:
And they don't even have the third option: 'coop un' with even emphasis, maybe more on the 'coop.' That's the billhilly way. 'coopon' seems pretty universal, otherwise. Putting the 'cyoo' sound in it is probably widely regarded, even here, as 'proper,' but no one says it.
I weep for those who try to properly learn the English language. Best bet is to just say what seems to work...now I wanna look at some of these charts...
edit: the soda thing...
Gotta imagine that's common. 'Coke' wins, but the other two are still fairly significant. Cultural/regional divide not found.
And one final question before I sleep...most of the country says 'poem' with two syllables? I call bullshit on this whole study. po-EM has never seemed common. PO-em always becomes one syllable when spoken. And once again, there is a group of tards, and they say 'poim.'