Crash Injury Rates by Mode of Travel

There was a study published in 2007 which took FARS (for traffic fatalities) and GES (for injuries) data, and combined with NHTS (National Household Transp Survey. 2001) data to try to quantify relative risk of fatality/injury by travel mode per trip. Full text and full .pdf are both available free online: Continue reading “Crash Injury Rates by Mode of Travel”

Is it really 20 times more dangerous?

I’ve been seeing, more often lately it seems, fairly bold numerical statements about relative bike traffic safety; so to take this one from peopleforbikes for example (my emphasis added): “The problem is particularly glaring here in the United States, where bike injury and fatality rates are roughly 20 times those of the cycling-friendly countries of western Europe“. Continue reading “Is it really 20 times more dangerous?”

Is Bicycling Safe? Is Bicycling Dangerous?

Short answer: As with all modes of transportation, it entails some danger.

Longer answer: yes, similar to the risk of motoring — perhaps twice as risky. but how to measure? (per mile, per trip?). Bike-MV collisions are currently running 2% of all in AZ. Bicycling represents perhaps 1%, i.e. twice the risk.

For the moment, this is going to be a catch-all for links and related info on the topic. Links:

Continue reading “Is Bicycling Safe? Is Bicycling Dangerous?”

How Risky is it, Really?

There’s a wonderful book written by author and former journalist David Ropeik that explains risk perception (and MIS-perception) in elemental terms; How Risky is it, Really?.

His explanations go all the way down to the biological and evolutionary level — think adrenalin, amygdala, and the fight/flight response — and it’s all very fascinating. Everyone should read it.

More to the point here, his “confessions” as a former journalist i think go a long way to explain the persistent problems with media stories regarding risk (p. 165):

Before I go on, mea culpa. I was a daily television reporter for 25 years, and most of the things that journalist do that make the world sound like a riskier place than it is, I did…. I regularly played up the dramatic aspects of my stories, emphasizing the negative or the frightening or the controversial, and deemphasizing (or omitting altogether) the aspects that would balance things out of put them in perspective… I never lied… But I did what most journalists do: I made choice that would make my stories more newsworthy, more dramatic , and more likely to attract attention. And that left my views with a distorted and more alarmning view of the world than was actually the case.


In chapter 2, Bounded Rationality, he explains several shortcuts we (everyone) use to determine whether something is safe vs. risky. Among them is how any particular issue is “framed”; this is critical in any sort of news story. Consider the following two statements:

Statement 1; actual quote from an AZ Rep news story on the BSAP:

Last year, 19 bicyclists died and more than 1,500 were injured, according to new Arizona Department of Transportation statistics

Statement 2; re-framed in terms of overall traffic safety

During the study period,  bicyclists accounted for only 1.5% of all traffic collisions, and less than 3% of traffic fatalities, according to Arizona Department of Transportation statistics. This indicates that bicycling is a small part of a very large problem

Which sounds scarier to bicyclists? Which reinforces notions of danger? Is 1,500 injuries (or 19 fatalities) a lot, or a little?

The thirteen Risk Perception Factors

  1. Trust
  2. Risk vs. Benefit
  3. Control
  4. Choice
  5. Is the risk natural or human-made
  6. Pain and suffering
  7. Uncertainty
  8. Catastropihc or chronic
  9. Can it happen to me?
  10. Is the risk new or familiar?
  11. Risks to children
  12. Personification
  13. Fairness

These factors fuel what Ropeik terms the Risk-perception Gap; which leads to poor decisions being made both by individuals and by society.

Free Range Kids

Along the same idea, is so-and-so’s book Free Range Kids, which I am now reading (Jan 2012)