It’s common knowledge that air travel is safer than travel by automobile (sorry, no cite). I’ll buy that some statistic out there confirms this. The crucial question is, which statistic?
Ignoring non-fatal injuries, I imagine there’d be two basic approaches for a creating a comparison: fatalities per person-mile of travel or fatalities per person-hour of travel. Of the two approaches, I’d argue that the latter is the more meaningful. Planes go much faster than cars, therefore the mileage based comparisons underestimate air travel risk. What the average earthling wants to know is if he/she spends 10 hours flying versus 10 hours driving, which more likely leads to their untimely demise?
Of course there are other meaningless comparisons one could construct. For instance, one could compare the total annual fatality rate of air versus automobile travel. There are more people-miles as well as people-hours driven annually than flown annually, so such a comparison would inevitably demonstrate the superior “safety” of air travel.
Cynicism being in vogue this year, I’d like to know how the air travel safety cognoscenti concluded that I’m less likely to buy the farm flying than driving? If it was computed in terms of people-hours, then hats off to them.
And a related question, how did the car racing safety cognoscenti conclude that their mind-numbingly tedious pastime (Look, here they come…ZOOM…uh…there they go) is safer than conventional driving?
Stats for flying from “Come Back Alive” by Robert Young Pelton:
“Flying’s well-earned safety statistics make perfect sense if you stand back and look at the big picture. There are 12,000 airliners in the sky making over 15,000,000 flights carrying 1,300,000,000 passengers annually. With all that activity, worldwide there are only 50 to 75 accidents that destroy commercial aircraft (including jets, small turboprops adn cargo planes) every year.”
It goes on:
[paraphrasing]
accident rate for
commercial jets = .8 per 100,000 hours of operation
turboprops (commuter jets) = 3.2 per 100,000
small planes = 11 per 100,000
2 fatalities for every 100,000 hours of operation for small planes.
For cars, the info. is a little more sparse:
40,000 people killed in the US each year
3,000,000 injuries in the US each year
Fatalaties are 40x higher in Egypt compared to the US and 10x higher in South Africa
When they measure fatalities to compare safety records, they use “passenger miles” for, cars (subdivided: personal, trucks, and busses), planes, and trains.
You can usually find the most recent figures (with some historical sampling) in any copy of The World Almanac and Book of Facts.
Here’s one estimate of the deaths per hour for variou activities including driving and flying:
Activity # Fatalities per 1,000,000 exposure hours
--------------------------------------------------------
Skydiving 128.71
General Aviation 15.58
On-road Motorcycling 8.80
Scuba Diving 1.98
Living (all causes of death) 1.53
Swimming 1.07
Snowmobiling .88
Passenger cars .47
Water skiing .28
Bicycling .26
Flying (scheduled domestic airlines) .15
Hunting .08
Cosmic Radiation from transcontinental flights .035
Home Living (active) .027
Traveling in a School Bus .022
Passenger Car Post-collision fire .017
Home Living, active & passive (sleeping) .014
Residential Fire .003
This is taken from the Bicycle Helmet Statistics page, which quotes it from “Failure Analysis Associates, Inc.” whatever that is. I guess “general aviation” includes small airplanes flown by amateurs, making them more dangerous than airlines.
Anyway, it appears that the airline is not the safest form of transport - school buses are.
By hour, school buses are safer, but by mile I’ll bet airlines are much safer.
General aviation is a term that refers to all civil flights in the US that are not scheduled airline flights. This includes personal flying, but around 70% of general aviation flights are revenue producing and are flown by commercial pilots. I would say that it is less safe than the airlines because there is more freedom and less regulation in GA than in the airlines.
To illustrate this, I read somewhere that when airline pilots fly their own personal aircraft under GA rules they do not have significantly better accident rates than rest of GA pilots.
I completely disagree, but then again I’d rather not be an average earthling. When I decide to drive (or fly) somewhere, it’s generally speaking because I want to go there, not because I’d like to spend some quality time on transportation (recreational motorcycle rides aside). So what I consider a meaningful statistic is the one that compares the risks of a flight to, say, Paris (duration: two hours) with driving to Paris (duration 8 hrs 15 min). Hell, throw in the train ride for the heck of it.
Even if you were to convince me that I’d be safer driving a car for two hours than flying for for two hours, I do not care, because that’d strand me in the outskirts of Bremen and I wanted to go to Paris.
There is a point to be made here, though not exactly the one in the OP: IIRC, start & landing carries higher risks than cruising at altitude, so shorter flights are on the average more risky than longer ones, per mile or per hour. If you were to somehow compute this into the stats, it might perhaps help to explain why GA is riskier. (Of course, shorter flights are often serviced with smaller planes, and so they don’t add that many passenger-miles (or hours) to the pool). And shorter flights actually compete with other forms of transportation, so the stat might even have some real-life usability.
I note from the table of safety statistics above that the safest mode of transport is a car that is on fire following a collision, and that being in a burning house is considerably safer than average living (including sleeping). I must remember to set my house on fire this evening before I go to sleep.
S Norman, you can drive to Paris in 8.25 hours? I wish we had roads like that in Ireland.
I’m not conscious yet, so I’m not going to do a search. There was a thread a while ago about putting parachutes on aircraft. I posted some statistice that I found on the AOPA site. First, most aircraft accidents are not fatal. Second, you are eight times more likely to be in an accident in a car than you are in an aircraft. But you are eight times more likely to die in an aircraft crash than a car crash.
I go with SpinyNorman on this. All these statistics are useless. If I want to travel between LA and London, the airline/auto statistics are meaningless. Likewise if I was going from Brooklyn to Queens.
The only meaningful comparison would be on trips which have reasonable alternative transportation methods, such as from New York to Boston or Baltimore. Then, if you calculate the average injuries per trip, that would be a useful thing to know.
Firstly, thank you all for excellent information. I wonder if it’ll ever be possible to determine on what basis the sweeping, “Air travel is safer than car travel,” statement was made? Well, even if not, we’ll know by which comparisons it is safer and by which it is not.
Now onto Spiny’s point:D (there’s no way I’m the first to say this, right?):
I agree there are travel concerns that are allayed by flight being safer on a strict per mile basis. You’d like to travel to Paris, I’d like to go to San Diego (we’re in the doldrums of the NYC winter). If my fear of fight were so extreme as to make me contemplate the (over 3000 mile)trip by car, then I’d find some comfort in a statistic that showed the flight safer than the road trip.
But, Spiny, other type of questions concerning the relative safety of air versus auto travel are possible. Let’s say I have a two hour round trip commute by car that I make each each day. Twice a month, though, I take a one hour shuttle flight (two hours roundtrip, time driving to airport ignored for simplicity) to a nearby city. We’ll my question is, on which of these days is transportation more likely to kill me? As you alluded to, Spiny, making the trip by car is impractical, I’m not even considering it. But should I hug the kids a bit longer on my flying days or my driving days? To answer this question, we need the safety comparison to be on a per hour basis.
But you should care, Spiny. Given that planes travel faster than cars, it’s easier for them to be safer on a per mile basis than on a per hour basis. Simple math. I’m not saying that if airlines miss the per hour mark, I’m staying on the ground. Instead, Spiny my point (boy is that fun to say) is different comparisons are possible and these have different meanings. Air travel that exceeds the safety of auto travel on a strictly per mile basis is not as safe as air travel that is safer on a per hour basis. If I were a corporate type working at an airline, whichever of these comparisons is true, I would put out the word that flying beats driving.
Also, Spiny, please keep in mind that the question driving me to distraction is:
** As I pointed out in the OP, many meaningless, but statistical sounding comparisons can lead to the conclusion that flying is safer than driving. So how was this safety conclusion made? People-miles? People-hours? Annual deaths?
Do we indeed? I am not a statistician - I’m not even sure I know how to spell it - but if you calculate the risk on a given flying day by adding up about 1000 low-risk passenger-miles or two higher-risk passenger-hours, you will arrive at the same risk for the given flight, won’t you ? And while that risk might be higher than the risk you run while commuting, it’s not as if anyone’s trying to cheat you. The information is right there: X miles at Y% risk, grab your calculator.
Well, perhaps it isn’t, due to the somewhat higher start & landing risks I guessed at earlier. Not that those would show up on a passenger-hour statistic, either. I’m still hoping a trained statistician shows up to get us out of this mess.
Obviously, stating that “X is the safest form of transport there is” makes no sense unless you specify your method of measurement. If that’s your point, I don’t think you’ll find anyone disagreeing, except perhaps a couple of airline advertising executives.
IMHO, passenger-miles is by far the most relevant comparison available - because I transport myself to get from A to B. I do get your point that fast transportation get better stats on passenger-miles than slow transportation, all other things being equal, but I believe that this is an instance of the most practically applicable statistics for real life incidentally being beneficial to someone - in this case, the airlines. Live with it.
What exactly is the mess here? I think per-mileage fatality rates are just per-hour fatality rates divided by average speed of each method of transportation. They are just two ways of describing the same data. (Though converting from one to the other is not trivial, since “average speed” is difficult to determine, esp. for cars.)
In any case, they are just averages, for average speeds and distances.
Oh yeah Spiny? Well I think I’m right and you’re wrong.
Seriously, though, this is a simple demo of different strokes for different folks. Didn’t Polycarp recently say something about this concept?
I hope you’ll suffer me one more attempt to convince you that the mileage based comparison may be less relevant than you propose.
In your original response to this thread you mentioned that a trip to Paris is 2 hours by air from you, but 8+ hours by car. IMO that’s a long car ride, but not prohibitively long. If driving were safer, and you were predisposed to a risk reduction mode of thought, you could drive. In this situation, having a mileage based comparison of risk allows you to choose the safest method of getting from A to B.
However, when I fly, for instance from NYC to San Diego, considering the distances involved, driving is not even a remote possibility. I never even contemplate the relative risk of flying these 3000 miles versus driving them, because my boss won’t give me the 2 extra weeks off it would take to make the round trip by car. I suggest that with much air travel, even when the distances involved are considerably shorter, the relative safety of flying versus driving is not a component of the decision as to how to travel. As above, time pressure creates a risk-independent motive for the selection of air travel over any other transportation. And if you can’t contemplate traveling that far by car, of how much use is the mileage based risk comparison?
Maybe many people would use a mileage based comparison the way you seem to be suggesting they would. Consider the relative risk of taking the trip by car versus by plane, and choose the safer mode of transport. I don’t this is realistic, though, since (A) time pressure is frequently the overriding concern when selecting a mode of travel and (B) the actual level of risk involved with either mode of transportation is sufficiently low that most folks file it into the, “It’ll never happen to me,” file.
The time based comparison has an entirely different application. It’s not to determine how to travel. As stated above, I consider risk to be a relatively minor component of this decision. Instead, time-based comparisons allow one to ponder one’s fate once the decision to fly has been made. Like the example in my previous post, “I’m flying two hours today. Usually I drive two hours. Do I have a higher or lower risk of dying today, and by how much?”
Moral: No matter how far you go in life, you still need to get it all done within in a lifetime.
which is why I put IMHO in front of my paragraph, thus marking it as my opinion.
Comparing the drawbacks (risk, discomfort, price) of different means of transport without factoring in how much transportation they actually deliver sure seems unfair to me.
But I’ll admit that you had me bedazzled for a minute - it would appear that you’re not primarily comparing the risk of flying to other forms of transport. It’s more as if it’s a matter of getting a grip on the risk by comparing it to other activities with well-known risks, be they car driving or, for that matter, alligator wrestling. In which case, I completely agree, you’ll have to figure out the risk per hour. And if all you have is the risk per passenger-mile, factor in the average speed as as scr4 suggested.
I don’t know if anyone’s brought this up yet, but it doesn’t look like it.
Example: It takes me 5 days to drive the 3,000 miles from Sumpter, South Carolina to Sacramento, California (I did this one winter driving the Smurphmobile*). That works out to ~60 hours of driving at an average speed of 50 miles per hour.
Using the chart above, that puts me at a risk of 0.0000282 deaths for the trip (exposure of 60 hours as opposed to one million), or about 28.2 microdeaths (:)).
One time I flew out to CA to visit relatives, instead of driving. It took about 5½ hours. My risk is 0.0000008 deaths, or 0.825 microdeaths. The risk of death due entirely to the mode of travel is considerably less for commercial air travel. This is due only partly because it’s a safer mode of travel per hour. It’s also safer due to the reduced exposure to the risk.
If the airline was just as dangerous as your car, the risk (in the above example) would be about eleven times more for the automobile trip, due to the longer time spent at that amount of risk. Likewise, air travel would have to be about 10 times less safe than automobile travel for it to be a bad risk. I don’t think it would look like a good risk to most foks, though, because few cars crash and burn as dramatically as an airliner (although the Ford Pinto gets an “A” for effort ;)).
~~Baloo
*The Smurphmobile was a 1986 Chevy Sprint 4-door (equivalent to a Suzuki Swift 4-door). With only 48 hamsterpower on tap, that trip was an adventure!
So if I want to know if my driving across the country is safer than flying to same place, I need ‘per mile’
but if I’m deciding on a long weekend vacation, and am willing to spend up to 5 hours getting there, then I need know ‘per hour.’
That means that since I can drive to Niagra Falls or fly to London for the same time, I should convert per mile stats to per hour to make the decision- Should I bone up on my Canadian or British?
