I was in an agrument with a very intelligent friend about a week ago, discussing the safety of cars and airplanes. Despite my protests, he refused to believe that planes are a noticeably safer means of travel.
Now, he admitted that many more people are killed in car accidents, but he counteragrued that there are many more car trips vs. airplane flights. If those were factored into the equation, he guessed, then the wide gap between deaths wouldn’t be nearly as large.
Is he right? I suspect he is, though not to the degree he was claiming. I’ve been looking for some statistics for this, haven’t found any yet. Still, there must be over a billion car trips in the States per year - there can’t be anything close to that in airplane flights.
I was JUST thinking of posting a question almost exactly like this one not two minutes ago! Some user with problems had the temerity to ask me for help. Bah! Next time the user gets his account disabled and computer re-formatted…see if he bugs me again!
On a vehicle per vehicle basis I too wonder what the percentages of accidents between planes and cars is.
However, there are a lot of ways to spin statistics if you want to determine what’s safest.
Your chances per amount of time spent in vehicle?
Your chances per mile travelled?
Fatal vs. non-fatal accidents when they do occur?
Your chances as a member of the overall population (in which you’d be included even if you never flew a day in your life)?
There’s probably more. My guess is the airline industry quotes stats based on #4 and maybe #2 as that would provide the best looking (for them) stats.
If you consider fatalities per 100,000,000 passenger-miles, cars are more than 20 times more dangerous than commercial airliners. See http://www.apta.com/stats/safety/natsafe.htm
I just thought to go to the Bureau of Transportation webpage. Given the earlier thread where, if 110 people die per day by car, and 2 by airplane, mixed with the 1995 BoT data (I like to overwhelm my friend with statistics when possible)
This is extremely rough - I’m no expert, but this is what I came to:
By raw deaths
40150 car dead per year
720 plane dead per year
cars - 98%
planes - 2%
By mileage -
827 billion miles overall in '95
451 billion by car - 57%
355 billion by airplane - 43%
57% of miles, 98% of deaths
43% of miles, 2% of deaths
by number of trips -
1 billion overall in '95
813 million by car - 81%
161 million by plane 16%
81% of trips, 98% of deaths
16% of trips, 2% of deaths
I think I win. The mileage one is pretty damning.
Well, here’s something that I bet you didn’t think about.
All those per-mile statistics are pretty well established and verified–mostly because they make the airline industry look pretty good.
If you were to analyze them on a per person per hour basis though, things change. For any given individual, their chance of dying while in a car is about the same as their chance of dying while in a plane. This seems to reflect a basic human risk acceptance.
OK, you say, but for any given trip, you spend less time in the plane. Wouldn’t that make the plane safer?
Not necessarily! It turns out, on the same basis, ordinary life is twice as dangerous as either car or plane. So, the quick plane trip just allows you to re-enter the more dangerous ambient environment sooner.
How is that reconciled, if the rates just reflect basic human risk acceptance? Well, the danger of ordinary life is weighted–the older or more unhealthy you are, the more risk of dying you have. You’re less apt to be in a car or plane if you are old or unhealthy–you’re probably going to be in a bed at home or in the hospital. Twice as less likely, it seems.
Frankly, I don’t give an attempted aerial coition with a continually axially reoriented and linearly displaced toroidal pastry about the statistics. I hate to fly. I’ve driven over a third of a million miles personally, and never had a serious accident–or even a particularly close call. I think I’ll stick with that.
On the subject of the statistics, though, how do they come up with the “miles driven” information? I know the error in it probably isn’t statistically significant, but I’m curious as to how they know how many miles we’ve driven.
As RM mentioned they don’t know how many miles you’ve driven but they can come up with statistically meaningful averages.
Just a WAG but one way might be to look at used cars. Data is easily collected on used cars – how many miles are on the odometer and how old the car is. I’m no statistician but I imagine the sample from this alone could be considered statistically significant giving a fair approximation of how many miles are driven yearly.
Even the most mismanaged airline probably maintains its planes better than the AVERAGE person maintains his/her vehicle. (Yes, some people keep their cars in perfect condition, but a lot of people wouldn’t notice that their car has bald tires until they spin off a wet road and into a ditch.)
However, I believe that the majority of aviation accidents are credited to pilot error. I would assert that the average person with a pilot’s license is much more skilled and better trained at handling his aircraft than you or I is at driving our cars.
Life is a crapshoot. Eventually, something is going to end our life. What control we have over that depends upon what risks we are willing to accept.
[QUOTE]
*Originally posted by RM Mentock *
**Well, here’s something that I bet you didn’t think about.
All those per-mile statistics are pretty well established and verified–mostly because they make the airline industry look pretty good.
If you were to analyze them on a per person per hour basis though, things change. For any given individual, their chance of dying while in a car is about the same as their chance of dying while in a plane. This seems to reflect a basic human risk acceptance.</b>
Interesting opinion.
I’ll note I was looking at it from the perspective of ‘what are the chances once you’ve decided to take a trip in this given vehicle’.
The immense mass of car-related deaths would seem to invalidate ‘is about the same’. Even the most conservative measurement I’ve run into - the one I calculated this morning, in fact - is 11 to 1 car before plane, and it wasn’t per-mile, it was per-trip.
Sure, if you’d never gotten inside a car or a plane in your life, then your chance of death by travelling in these vehicles is zero, of course. But very few people have, and you can’t prove they never got into one until they’ve already died. The statistics reflect the people that chose to take trips.
Not sure if I understood your reasoning correctly, RM.
Just to be clear, the stats for airline accidents only include the major carriers. Commuter aircraft have accident rates that are much worse, almost on a par with autos. And general aviation (you in your Cessna) has an accident rate worse than autos, but not horribly so. About on par with motorcycles.
As for the major airlines, there is no way you can massage the statistics to make them look more dangerous than driving your car. You can come up with stats per trip, per mile, per hour, per takeoff and landing, whatever you want. They ALL come out better than driving a car. There’s just no way to argue around it.
The numbers say airplanes are safer…at least until the Concorde went down…but no one factors military crashes into the equation. The stats refer to ‘passenger’ miles, which means ‘paying passengers on commercial airlines’.
Even so, it is natural to think that cars are safer. When you are driving a car, you have the illusion of being in control of your fate. And you can still scream directions to the driver from the back seat if you happen to be a passenger.
An airplane is different. You crowd into a little seat and, after a suitable period of waiting to enable your adrenaline to pump up, this huge metal cylinder, wings flapping and hydraulic pumps groaning, abruptly lifts into the sky. Then the flaps and slats come up. Then the gear comes up.
A flight attendant who looks like he (or she) needs another couple Valium start passing out snacks. By this time many people have concluded that their last meal is going to be Planter’s Dry Roasted Peanuts and Sprite.
The chief attendant tells you what to do in ‘an emergency’. Like the plane is just going to glide slowly to a calm spot in the middle of the ocean, land safely on the water and wait while you get your floation device out from under the seat; proceed to the nearest exit and slide down the escape ramps. All the time you are thinking “bullshit, it’s 4 minutes of firey hell from this altitude until I hit the concrete.”
And you don’t know who is driving this thing. Sure, you saw a couple guys with black uniform coats with fold stripes on the sleeves and hats go into the cockpit, but one or both may have a heart attack in 6 minutes. Or be suicidal. Od decide he needs slaves to work for him in the netherworld.
Halfway through the trip right after you gnawed at something called ‘icelandic sole with figberry torte’, you hear "This is the Captain…We might have a little turbulence up ahead, so if you would please remain in your seats with your seatbelts fastened and snug, the flight attendants will be passing out barf bags to those who need more than one, and some smelling salts.
I can go on for another hour, but maybe MPSIMS is a better place.
Point is, you don’t feel you have control of your own life in an airplane. That’s why people don’t like to fly.
That 11 to 1 ratio is pretty close to the one I calculated to produce my statistics. Look at the numbers that bibliophage posted, .95 per 100M passenger miles for autos, and .04 for airlines. Actually, the airline ratio fluctuates a great deal more than the auto ratio…some years it’s three or four times that. Using 1992 info, for instance, the airline figure is .09. That ratio of .95 to .09 is approximately 11 to 1, as you have. Let’s start with that.
Now, how do we calculate a statistic ratio based upon per person per hour? We divide each figure by the average speed. Since airline speed is typically ten times the auto speed, we get 1.1 versus 1.0. About the same.
In other words, your chances of dying in a car are about the same as your chances in an airline, hour for hour. On a trip basis, since auto travel takes ten times longer for the same distance, the ratio is 11 to 1, as you’ve said–but the overall risk of death is twice that! So, if you spend twenty hours in a car getting somewhere, you’re actually better off, because after your two hour plane trip, you spent 18 hours in a more dangerous environment: life.
Statistics have shown that flying is safer. Whoopie do da day! I’d rather take my chances on the ground, where survivability in the event of a crash is quite a bit greater–if your plane crashes, there’s a percentage chance of surviving that is near enough to zero as to be virtually indistinguishable from zero.
That didn’t quite come out the way I meant it. The overall risk of death is for all life activities…in other words, 24 hours a day. It’s about twice the per hour risk for airline travel or auto travel.
Exactly. And no amount of statistics is going to convince those people, because most people think they are better than average drivers. Or these days, most people think their car is safer than average. In any case, most of us think car accident stats don’t apply to us.
