## Tuesday, April 28, 2009

### You Do The Math - Is it safer to fly?

Ever hear the phrase, "It's safer to fly"? Do you think that's true? Let's find out for ourselves. Using the World Almanac deaths from motor vehicle accidents ranged from 55,000 to 40,000 a year from 1970 to 2003. Deaths from airline accidents ranged from 0 to 342 from 1985 to 2004, not including 2001 when 531 people died. Seems safer to fly, right?

What happens when we calculate deaths per mile traveled? After all, you have a choice to either fly to Chicago or drive. The difference in time is an hour or two, and avoiding hassle at the airport might sway some travelers to drive.

But how many people have decided to fly because they thought it was safer? Let's find out for ourselves if it really is safer, because today You Do The Math!

From the World Almanac, whose information is from the FAA and the Air Transportation Association of America, we have the left two columns, deaths and miles flown. Dividing miles by deaths, we get the right column, miles per death.

Year....Deaths......Passenger Miles Flown......Miles per Death

2007......0.............829,033,000,000..........< infinity >
2006.....50.............796,795,000,000.........15,935,900,000
2005.....22.............778,563,000,000.........35,389,227,272
2004.....13.............731,926,000,000.........56,302,000,000
2003.....22.............655,850,000,000.........29,811,363,636
2002......0.............641,102,000,000..........< infinity >
2001....531.............651,700,000,000..........1,227,306,967
2000.....89.............692,757,000,000..........7,783,786,516
1999.....12
1998......1
1997......3
1996....342
1995....160.............540,656,000,000..........3,379,100,000
1994....239
1993......1
1992.....33
1991.....62
1990.....39.............457,926,000,000.........11,741,692,307
1985....197

It seems you have fly several billion miles before your number is up. Does anyone out there fly that much? Now let's see how autos compare.

The National Safety Council reports 40 to 55 thousand annual "motor vehicle deaths", which includes an average of 5600 pedestrians a year, several hundred bicyclists, and two or three thousand motorcyclists. Just including deaths from cars and light trucks crashing into things, or rolling over, the numbers drop significantly. This is in column three.

The FHA, the DOT, and the IIHS also report stats on miles driven per licensed driver and licensed drivers per 1000 residents. We have to use the US population from the Census Bureau to figure total miles driven. (Since we only have 2004 and 2000 census data, we need to take a fourth of that 4 year growth, and estimate each year's population in between.)

(number US residents / 1000) * (number licensed drivers per 1000 residents) * (miles per licensed driver) = total miles driven

Now we simply divide total miles driven by deaths in passenger vehicles to see the last column, miles per death.

Year..Total.....Deaths in....Miles Per.....Licensed Drivers....Number of US
.....................Vehicles.....Driver.........residents
2007................................................................................301,621,157
2006..42,642..30,012........14,862.......677.....................est.298,965,906
2005............................................................................est.296,310,655
2004................................................................................293,655,404
2003..44,800..35,500........14,737.......675.....................est.290,597,361
2002..44,100..34,776...................................................est.287,539,317
2001..43,788...............................................................est.284,481,274
2000..43,354....................................................................281,423,231
1999

Year.....Total Miles Driven........Miles per Death
2006.....3,034,783,591,121.......101,119,005
2003.....2,890,709,983,613........81,428,450

I'll have to fetch all my almanacs to calculate several more years' worth of data, but since auto deaths and miles driven are a lot more consistent than airline deaths, then it's safe to say for now that driving is a lot more dangerous than flying.

You have to drive a car or light truck between 80 and 100 million miles before meeting your maker, compared to the 1 billion to 56 billion miles you have to fly. When you do the math, driving is between 12 and 691 times more dangerous.

However, according to the History Channel, 86% of all motor vehicle related deaths are not on the interstate. Also, the interstates acount for 20% of all traffic, but only make up 2% of all road miles. Therefore, the interstates have 10 times the traffic density, yet have 6.14 times fewer fatalities. One could say they are 61 times safer than city driving.

Also, keep in mind other factors, such as type of vehicle you drive. For instance, the 3500 to 4000 pound cars made from 1997 through 1999 had 90 to 95 deaths respectively per million registered, while the same weight pickup trucks had about 165 to 155 deaths, respectively. Thus, the cars were 45% to 39% safer.

Here are the results of DOT studies done in 1991 and 2001:

Many other factors exist making driving safer, such as time of day (avoid rush hours), time of week (avoid weekend nights), driver sobriety (avoid Zima), driver condition (be awake, and not upset), and weather (avoid fog, snow and ice).

Avoiding these conditions make driving many times safer, in fact alcohol alone accounted for 34% of fatalities in 2003. In my home town, the three rush hours accounted for about 75% of accidents.

Combining all the right factors (sober driver, big car, interstate, not rush hour, nice weather, well rested and a happy disposition), and driving might become just as safe as flying. Driving to Chicago with all these factors might be just as safe as flying, as long as you stay on the interstate.

However, if you drive drunk in rush hour in town in the rain, suddenly we find that driving is a lot more dangerous than average. Instead of being 691 times more dangerous than flying, then it's perhaps (wild ass guess here) 691 times 691 times more dangerous, or about 477,000 times more dangerous. That's worse than riding a motorcycle.

And don't forget about flying abroad. The last I read, flying in Latin America or Africa increases the risk a few times over. Yet flying in the Middle East was the safest. Japan and Europe also had good records. Don't forget Australia (but I did, sorry).

James said...

I've always thought it was stupid to say flying is safer than driving for this very reason.

But there are more factors to consider:

How many flight deaths came from commercial passenger flights vs. charter flights?

What is the skill of the individual driver? Unlike flying, the driver can influence their chances of dying. So maybe for some drivers flying is the best option.

WoodHugger said...

So true, many people should only take public transportation. On the other hand, many pilots should not be flying. Most crashes are due to pilot error, according to Steve's Dad, Col. Jerry Bowline, test pilot who "flew everything".

Deaths probably do vary from plane to plane. I don't think I've ever heard of a 747 crashing, except maybe from terrorist attacks. But the 737 and DC-10 had "teething problems", to say the least.

On the raod, a 4000 pound anything is the safest vehicle in it's class (car, pickup, SUV), cars being the safest. Pickups are much more dangerous, while SUV's fall between pickups and cars.

So, if it takes 80 million miles for the average driver to die, switch to a small pickup or large pickup, and that figure drops to probably 60, 40 or 20 million miles. Small cars are safer than small pickups, but about as safe as large pickups.

I've heard, but have no data to prove it, that a motorcyclist dies every million miles ridden. So, in a bad year (2001), even a motorcycle is about as safe as flying.

Walking, however, is really bad. With 5600 deaths a year, and how many miles do people walk in traffic? About a few hundred a year for serious walkers and/or city dwellers. I once did the math and it came to something like you are 64 times more likely to die per mile walked than per mile driven. That's WAY worse than flying.

WoodHugger said...

Ooops, forget what I said about motorcycling being as safe as flying. The data for airline miles flown were listed in BILLIONS. I had them listed in millions. Therefore, flying is 1000 times safer than what I had been thinking all these years! (Note to self: Don't forget to read the fine print.)