Transportation safety in the United States

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Annual US traffic fatalities per billion vehicle miles traveled (red) and miles traveled (blue) from 1922 to 2012.

Transportation safety encompasses automobile accidents, airplane crashes, railroad and motorcoach fatalities and maimings, and other mass transit incidents. Safety overall has steadily improved in the United States for many decades. Between 1920 and 2000, the rate of fatal automobile accidents per vehicle-mile decreased by a factor of about 17.[1][2] Except for a pause during the youth bulge of the 1960s (a time when many young, inexperienced drivers were on the road), progress in reducing fatal accidents has been steady. Safety for other types of U.S. passenger transportation has also improved substantially, but long-term statistical data are not as readily available.[citation needed] While the fatality rate roughly leveled off around 2000–2005 at around 1.5 fatalities per 100 million miles traveled, it has resumed a downward trend and reached 1.27 in 2008.[1]

One can also calculate auto fatalities per driver's license. From 1990 to 2009, this number has also been declining: from 1 death per 3,745 driver's licenses in 1990 to 1 per 6,200 driver's licenses in 2009.[3]

Following an approach used by several writers,[4][5] one can compare the likelihood of a fatal accident while driving and while flying with a scheduled airline. This is most meaningful for trips in which either mode of transportation is a reasonable alternative. For the US, a typical trip of this sort is from the Boston area to the Washington, D.C. area, about 6 hours door-to-door by air travel and 7 hours door-to-door by automobile. To compare typical risks, one needs to have both driving and flying statistics expressed in comparable units. For driving, one can use the US average fatal automobile fatality rate of 1.5 per 100 million vehicle-miles for 2000[1] and then translate it into passenger-miles (to get a single-person risk exposure). For flying, one can use a statistic such as the US general and commercial aviation fatality rate, which was 1.9 per 100,000 flight hours for 2000,[6][7] which again needs to be expressed in passenger-miles (e.g., if an airplane has 180 passengers, then the passenger miles are 180 times higher, which translates into a considerably lower fatality risk on a per passenger basis; also, most travelers are concerned with the potential risk of passenger commercial airlines, which are significantly different from general aviation statistics which include small non-commercial airplanes). The number of deaths per passenger-mile on commercial airlines in the US between 1995 and 2000 is about 3 deaths per 10 billion passenger-miles.[8]

   Risk estimation (per passenger) By air   By auto
   Flight miles                       400        0
   Risk (millionths)                 0.12        0
   Miles driven                        40      450
   Risk (millionths)                 0.60     6.75
   Total risk (millionths)           0.72     6.75

Note: The driving stats used above are vehicle-miles instead of passenger-miles, this equates to an assumption that only one person travels per car which is clearly incorrect. Assuming (fairly arbitrarily) an average of 2 passengers per car, the stats look like this:

   Risk estimation (per passenger) By air   By auto
   Flight miles                       400        0
   Risk (millionths)                 0.12        0
   Miles driven                        40      450
   Risk (millionths)                 0.30     3.38
   Total risk (millionths)           0.42     3.38

The likelihood of a fatality (per passenger) estimated for this trip (assuming a total of 40 miles driven to and from the airports), is about 8–9 times greater when driving than when flying.[9] Also notice that in this scenario a fatality is 2.5–5 times more likely on the drive to the airport than on the flight itself.[10]

Rail and motorcoach accidents also account for fatalities, although public transportation is far less dangerous than driving a personal vehicle.[citation needed]


See also[edit]

References and notes[edit]

  1. ^ a b c "Fatality Analysis Reporting System". U.S. National Highway Traffic Safety Administration. 
  2. ^ "Making Sense of Highway Data". U.S. National Motorists Association. 
  3. ^ "Table 1105. Fatal Motor Vehicle Accidents—National Summary: 1990 to 2009". U.S. Census Bureau. 
  4. ^ Arnold Barnett (1991). "It's Safer to Fly". Risk Analysis 11 (1): 13–14. doi:10.1111/j.1539-6924.1991.tb00558.x. 
  5. ^ Peter B. Ladkin (1997). "To Drive or To Fly". University of Bielefeld. 
  6. ^ Rathmann, Kimberly. "General Aviation – Accidents and Fatalities". Retrieved 15 November 2013. 
  7. ^ "Figure 1 – General Aviation Fatality Rates: 1975–2000". U.S. Department of Transportation. Retrieved 15 November 2013. 
  8. ^ Aircraft Accidents in the United States, 2006
  9. ^ Calculated as 6.75/0.72 and 3.38/0.42
  10. ^ Calculated as 0.60/0.12 and 0.30/0.12
  11. ^