I’ve heard similar statistics about commercial air travel being much safer than driving on a per mile basis, and i certainly believe the statistics. After all, there is a lot of empty air up there; in a car you whiz by trees and other cars.
But i’m not sure that comparing air travel to normal average driving is truely the most appropriate comparison. If I am comparing the danger in driving from Wash DC to , oh, say… Baton Rouge, versus the danger in taking Delta for the same trip, i don’t care about the statistics for normal average driving.
Although i have no information to back it up, it seems like driving on the interstates between cities is much safer on a per mile basis than your average driving. If i can personally assure myself that i will be driving perfectly sober, during the day, and stopping for the night when i get even slightly drowsy, then my odds of fatality per mile have dropped to MUCH MUCH lower than the ones normally attributed to driving.
Now THOSE are the stats i would like to see to make the comparison. It is not obvious that commercial air travel would be safer then (though it would still be quite believable, just not obvious without doing the research).
just my two cents…
-Luckie
What that article does, using essentially the same data, is compute the rates on a per trip basis, but not equivalent trips. Suppose, on average, we have for every one plane trip of 2000 miles, 100 car trips of 20 miles–which might not be a bad approximation, right? Then the number of miles traveled is the same, so the deaths on the car trips will be 11 times the deaths on the plane trips. But if you then compute the statistic on a per trip basis, you’d divide 11 by 100–so the ratios get reversed, and airlines have ten (OK, nine) times the deaths of automobiles on that basis.
However, he gets hung up in all this juggling. He makes the statement: “If you flew a Boeing 737 to work every morning and back, you’d be far more likely to die in a crash than if you drove a car.” Now, he’s clearly comparing equivalent trips. On that basis, you’re ten times more likely to die in a car, because you spend ten times more time in the car making the trip. In other words, he’s got it flat out backwards, at least as far as that statement goes.
I may be making a poor assumption here, but quite a few of the reasons you might die in a non-car or non-airline related accident would also apply to your time in a car or airline as well. So it can not really be twice as dangerous.
For example, a man dies of a heart attack on a plane to denver, his statistic doesn’t fall under airline deaths. A guy in a passing car could shoot your buddy in the back seat.
This is the exact opposite of other statistics. Alcohol related accidents include accidents were a driver was sober, but the pedistrian he hit was drunk.
I am sticking with the theory that birth is still the leading cause of death.
So what we really should be comparing is whether an airplane ride is safer than driving the same trip in a car. For example, next week I’m travelling to a city that’s about 200 miles away. I still haven’t decided whether I would rather fly or drive. It takes slightly longer to drive this than to fly (because if I fly, I have to go to the airport, park, wait, rent a car, etc.), but an advantage of driving is that I can do it when I’m ready and not have to wait for Southwest Airlines’ schedule, so I could likely get home sooner by driving.
But suppose I’d also like to compare relative risks. The statistics for the plane trip (deaths per passenger-mile) are probably skewed too low in this case, since the trip is shorter than average, and most accidents happen at takeoff or landing. If the 0.04 number is for trips that average 1000 miles, then maybe this trip should be adjusted to around 0.15.
And the statistics for car risk are probably skewed too high, since they include mostly in-town driving, which is (I think) more dangerous. The trip I will be taking is straight down an interstate highway, so it’s probably much safer on a passenger-mile basis than the DOT statistics. Does anyone have any idea about the “deaths per 100 M passenger-miles” number that would apply to interstate driving? My WAG is that the 0.95 number should be adjusted down to around 0.3.
Then you’d need to figure that if I fly, I will still be doing some driving on city freeways to and from airports, and some of it will be in an unfamiliar car. All together, it seems that flying is marginally safer than driving, so I’ll probably make the decision based on convenience vs. cost.