A few years ago, a Yelp user going by "Cindy I." had enough with slow drivers in Portland and Beaverton. "Why so many?" she asked.

Andrew C. responded: "This is a good damned question. And when you figure out the answer, you tell me."

Maybe it's politeness, pot and Priuses (or Prii).

One thing's for sure: Slow Oregon drivers aren't just traffic hyperbole. A new "Lead Foot" study by Progressive Insurance found that Oregon has some of the nation's slowest drivers - and that's a very good thing, the company contends.

Using data from 12 billion miles recorded by Progressive's Snapshot devices, which policyholders plug into their cars hoping to save money on insurance premiums, the company determined that the median speed of Oregon drivers is 31 mph.

That qualifies it as one of the nation's eight slowest states, with drivers in heavily congested Washington, D.C., the slow-pokiest at 24 mph.

Progressive says the fastest drivers live in Alabama and Mississippi, where the median speed is 40 mph, meaning half of all driving in these states is faster than 40 mph and half is slower.

Cindy I. might believe basic manners, the free flow of commerce and even evolution itself demand motorists move as quickly as legally possible.

But the Lead Foot report maintains that higher speeds result in more hard braking ... which is typically a sign of tail-gating ... which leads to rear-end crashes ... which accounted for most of the nation's insurance claims in 2014.

"After analyzing Snapshot driving data, we've found hard braking to be one of the most highly predictive variables for predicting future crashes," said Dave Pratt, general manager of usage-based insurance for Progressive.

Interestingly, the study's slow-driving states also have the fewest fatalities per vehicle miles traveled.

In fact, according to the Snapshot data, people should think about ditching the four-second rule taught in driving school. You should keep even more distance between you and the car in front of you, the data showed.

Progressive found that the safest drivers allow an average of 39 percent more time and 32 percent more distance, respectively, to stop.

In fact, the data showed the average distance and time needed for a motorist to come to a complete stop without hard braking at 60 mph is 1,262 feet and 24 seconds - the equivalent of 4.2 football fields, or singing "Happy Birthday" three times in a row.

So why do Oregonians drive slower than people in most other states?

Maybe it has something to with the fact that the state has the West's lowest highway speeds. Off course, Montana, where the speed limit stretches to 80 mph on some stretches of highway, also registered at 31mph, tied with Oregon on Progressive's slow-speed index.

Maybe dawdling is just part of the state's culture. After all, its mascots are Beavers and Ducks, which aren't exactly known for breaking the sound barrier.

Or maybe that "Portlandia" skit is more accurate than we would like to admit.

Sorry, Andrew C., that's not much of an answer.

Come to think of it, Oregon drivers usually travel at less than the speed limit when I'm late for something. Is that just me?

America's slowest states, according to the Progressive report (with median speeds):

1. Washington, D.C. (24 mph)

2. Rhode Island (29 mph)

3. (tie) Massachusetts; New Jersey (30 mph)

4. (tie) Oregon; New York; Connecticut; Montana (31 mph)

America's fastest states, according to the Progressive report (with median speeds):

Alabama; Mississippi (40 mph)

Minnesota; Oklahoma; Tennessee; Georgia; Kentucky; Michigan (37 mph)

South Carolina (38 mph)

-- Joseph Rose

503-221-8029

jrose@oregonian.com

@josephjrose