Who Does Florida Think It Is?

a/k/a Linear Fun #3: Driving Across America

Plot total drivers vs. total population (using this table) for every state in the US and you get this graph:

Okay, that dot that’s below the line? That’s New York. That one’s easy. Fewer licensed drivers than you’d expect for the population ’cause only cabbies drive there or something.

But that dot that’s above the line? That’s Florida, and me and my classes will be damned if we can figure out why they’ve got more than their fair share of drivers.

Anybody got anything for us on that?

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I'm Dan and this is my blog. I'm a former high school math teacher and current head of teaching at Desmos. He / him. More here.

26 Comments

  1. That’s my thought.

    Stats here to compare Florida to the US overall.

    Fit retirees. Not too old to give up the car. But more than their share of people old enough to drive.

  2. I can’t decide who’s serious here. Florida’s senior citizen population probably figures into something somewhere, I just don’t know if it’s this.

    Didn’t TMAO live there?

  3. Interesting how perfect the line fits. I’d think there’d be much more fluctuation.

    And, again, THANKS SO MUCH for the help. So much THANKS I had to dedicate a post. You’ve made my job much, much easier.

  4. My guess is undocumented immigrants. On the census, they don’t exist. In the DMV, they do. Until very recently, this was possible in Oregon, but I don’t know if that’s the case in Florida or not.

  5. Ah, gotta love the stats, I mean there are numbers, and there are NUMBERS…

    First, What is the population figure? Is it 18+? Is it census based?

    Rick, they count in population, they are counted in census legal or not, so that wouldn’t do it.

    Dan, they DO drive! DH has done some work on drivers licensing policy issues. Florida has a reputation of NOT pulling licenses, so someone in NY traveling between the Empire and Sunshine state might prefer a drivers license from the south even while claiming New York residency. I hate to burst Sarah’s bubble, but they are not always fit to be behind the wheel.

    Lots of issues in Florida about purging voting rolls, Is it a surprise some of the same troubles might be affecting the licensing rolls too? Sylvia’s note suggest that. Put in a lot of people dying (due to older population) and not getting purged, and voila, your numbers are inflated.

    Mark’s suggestion is good, is it based on licenses, or car registrations?

    I’m wondering if all these little things are adding up. I think we should put this to Freakonomics, sounds like it might be up their alley?

  6. Interesting stuff here, team. Not sure how I’m gonna sell this to my kids with the same sort of satisfaction as New York, but this thread puts me 200% closer than I was.

  7. Dan: Having spent time with family in Florida nearly every year of my life, here’s another factor that might figure in: the landscape. Aside from the obvious exceptions there are no true pedestrian-friendly urban centers; Florida can easily be characterized as one big suburban sprawl strip mall. You *have* to drive to get anywhere.

    From the Florida DOT:

    Question: Who can tell me about traffic counts and other statistical information?

    Answer: The Transportation Statistics Office. You can call them at (850) 414-4848.

    So call them in class and put it on speakerphone.

  8. Dina, I live in FL and that’s what I was going to say, too. It is a soul-sucking truth here that everything is built to be driven to and from. I think we might be the driving-est state because most of the development here took place long after the advent of the automobile, as opposed to many places that have core areas that preceded it and thus are more set up for non-driving. Also, we fund our public transportation barely at all.

    Now I’m going to want to research this myself for numbers to back it up.

  9. Dateline: Orlando, Florida

    I’m one of those roughly 13,000,000 drivers. And contrary to Dan’s ranting about 30 being “over the hill” I’m nowhere near retirement age yet. But we do have more than a few folks. And I don’t know if this factors in, but we have the largest retirement community in the country (which I suspect means also the largest in the world) called “The Villages” about an hour north of Orlando. A few years ago, they set their minds on beating the former Guinness world record for the longest golf cart parade, and they mustered up almost 3,400 golf carts to make a line many miles long:

    I work at a camp that’s not far from there for a few weeks each summer. Most big stores, including WalMart, Home Depot, Office Depot, etc. have special golf cart parking lots just for the retirees. And please don’t plan to go out to eat dinner at around 4:30 in the afternoon…..

    OK, that might not really be completely focused on Dan’s question, but I suppose that those folks are still drivers, and they must keep a driver’s license to operate the golf carts (and I suspect that most all of them also own and operate automobiles). And Dan, I doubt that a 3,400 cart parade is really up to par with your other fascinating web content that we’ve discussed previously.

    Dina and Sandy make a good point about how everything sprawls here, so that everyone wants to drive everywhere.

  10. I say blame it on Canadians – and I am one.

    Every spring we see the parade of RVs arriving back home and many (most) are hauling a small vehicle with a FL plate.

    Canadians can be issued a FL drivers licence quite easily.

  11. Come on, folks, this one is so easy!

    At least three-fourths of Florida’s drivers are Ohioans wearing out the interstate to get the hell away from relentless snow squals, ice storms, fog, rain, sleet and whatever other hell-sent form of precipitation lands on us until July!

  12. Another couple of thoughts. Linear equations are useful for predicting the answer to a question, if the data fits. You could say that this graph might point to the fact that the prediction ability becomes less accurate for large states where the driver’s license bureau is underfunded. Seems like it works well for small states.

    Could this also be the fact that the variance of small states is swallowed up by the scale of this graph? So that a variance of a million or so people in Florida and New York is large enough to see on this chart, but that the same percentage variance in a small state would be too tiny to see?

    In other words, the gap is big because the state is big.

  13. Another hypothesis to add to the pile: Most states require you to have one and only one driver’s license — if you get a license from a new state, you surrender the old one — but Florida issues part-year residents a Florida license (valid in Florida only) whether or not they have another license. So that would seem to push up their numbers.

    (Look here, under “Part-time Resident”. I don’t know of anywhere else that does this.)

    I like the disproportionate-numbers-of-seniors theory, though I’d expect demographics to unbalance other states too. I don’t think the sprawl theory holds water, though: there are too many other states with no real walkable urban areas. Arizona? Nevada? Texas? I’d rather go without a car in Miami than Phoenix…

    Fun fact: Florida’s state song is “Old Folks at Home”.

  14. Dan, if the data is taken from registered VEHICLES, as opposed to registered drivers, there are a BUNCH of vehicles people own up here in CT that have residences in CT, yet their vehicles have FL plates. Cheaper taxes nad the like.

    I assume many spend time as “snow birds,” fleeing our wonderfully unpredictable winter weather here, thus justifying residency restrictions.

    Or I could be totally wrong. Not first/last time.

  15. While Florida may look the most interesting on the graph, they are not the most interesting in terms of the actual data.

    From the same site as Dan cited:
    http://www.fhwa.dot.gov/policy/ohim/hs04/htm/dl1c.htm

    Alabama has 798 licensed drivers per every 1000 total resident population (compared to Florida’s measly 756) and 1014 licensed drivers per every 1000 driving age population (compared to Florida’s 949). HUH?

    And how do you explain your line of best fit? A y-int of 200775?

  16. We also see a lot of FL plates here in the DC area. I’ve been told it’s because military personnel can choose a state from which to have a driver’s license and register their cars, so they don’t have to change that every time they move. Apparently many choose FL because it does not have a state income tax. I don’t know if that is true or if it would make a significant difference.