COMMENTARY

Fatality Risks on the Road and in Space On February 1, 2013, millions of Americans commemorated the 10-year anniversary of the loss of Space Shuttle Columbia and its 7-member crew. Much less visible, however, was the 10-year anniversary of the 122 automobile crash deaths that also occurred in the United States on February 1, 2003.1 Space travel and road travel do not pose competing risks and are rarely considered together in any context. However, the 2 anniversaries offered a time to reflect on the deaths associated with these 2 disparate modes of travel and an opportunity to consider why these events produce such discordant public responses. Funding: None. Conflict of Interest: None. Authorship: Both authors had access to the data and a role in preparing the manuscript.

Table

The United States has more automobiles than any other country on Earth, and about 87% of adult Americans are licensed to drive.2 In 2009, Americans collectively accumulated about 4.8 trillion kilometers of automobile travel (a distance equal to 16,000 round trips between the Earth and the Sun).3,4 Most trips did not result in a crash, creating the impression that automobile travel is uneventful, innocuous, and far safer than spaceflight. To examine the validity of this perception, we compared the fatality risk associated with American automobile travel to the fatality risk associated with American spaceflight. We determined the American spaceflight fatality risk by analyzing all crewed missions launched by the United States with a planned maximum altitude exceeding 100 kilometers (in accordance with the Fédération Aéronautique Internationale definition of spaceflight). Deaths during training

Comparing Space Travel and Automobile Travel* US Space Travel (50 years)

Basic data Average trip distance (km‡) Average trip duration (hours) Average trip velocity (km/h) Average vehicle occupancy (persons) Exposure indices Total number of trips (count) Total distance traveled (100 million vehicle-kilometers) Total person-distance traveled (100 million person-kilometers) Travel fatalities Fatal incidents (count) Travel-related fatalities (persons) Demographics Average age at death (years) Proportion male among fatalities (%) Proportion white among fatalities (%) Analytic comparisons Lifetime risk of travel-related death (%) Risk of fatal incident (per vehicle-trip) Risk of death (per 100,000 person-hours) Risk of death (per 100 million vehicle-kilometers) Risk of death (per 100 million person-kilometers)

6,264,294 237.1 25,646 5.3

US Automobile Travel (1 year)† 16 0.3 50 1.7

168 11 60

233,849,000,000 48,280 80,627

2 14

30,196 32,885

42 71 71

42 70 74

3.6 (2.0-6.0) 1.2
102 (0.2
102  4.6
102) 6.3 (3.6-10.8) 1.3 (0.76-2.3) 0.23 (0.13-0.40)

0.86 (0.81 - 0.92) 1.3
107 (1.3
107  1.3
107) 0.028 (0.027-0.028) 0.68 (0.67-0.69) 0.41 (0.40-0.41)

*Values in parentheses represent 95% confidence intervals. See Supplemental Appendix for assumptions, calculations, and references. †“1 year” denotes 2010 where possible and 2009 otherwise. ‡1.000000 kilometer ¼ 0.6213712 statute miles.

0002-9343/$ -see front matter Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjmed.2014.01.027

468 were excluded (eg, fatal crashes during flights planned for lower altitudes, the fatalities resulting from the Apollo 1 training launch pad fire), as was distance accumulated by crew residing on a space station between spaceflight missions. The fatality risk associated with modern automobile travel in the United States was determined using the National Highway Traffic Safety Administration database (drawing on data from 2010, the safest year on record at the time of the final Space Shuttle mission) and the most recent US Department of Transportation National Household Travel Survey.3,4 Between 1961 and 2011, the National Aeronautics and Space Administration (NASA) launched 168 crewed spaceflight missions, encompassing the Mercury, X-15, Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs (Appendix: Supplementary Tables 1-3, online). The average spaceflight carried about 5 crew members and traveled about 6 million kilometers over 10 days for an average velocity of about 26,000 kilometers per hour (Table). In contrast, Americans made about 234 billion automobile trips in 2009. The average automobile trip carried about 2 vehicle occupants and traveled about 16 kilometers over 19 minutes, for an average velocity of about 50 kilometers per hour.1 Evaluating total fatalities and transportation distances confirms that the risk of death during spaceflight is substantial. Approximately 1.2% of all missions had fatal outcomes, and 3.6% of US spaceflight crew (astronauts, cosmonauts, mission specialists, and others) died while on a space mission. These risks are a testament to the bravery of individuals who travel to outer space in the name of patriotism, scientific discovery, and human progress. One striking feature of the results is that the risk of death during automobile travel is, by some measures, similar to that of spaceflight. In both settings, those who died had an average age of about 42 years, about two thirds were male, and about two thirds were white. Moreover, the perpassenger-kilometer risk for automobile travel (0.41 deaths per 100 million passenger-kilometers; 95% confidence interval [CI], 0.40-0.41) was higher than the per-passengerkilometer risk for spaceflight (0.23 deaths per 100 million passenger-kilometers; 95% CI, 0.13-0.40). The comparative rarity of spaceflight and frequency of automobile travel also make the aggregate lifetime fatality risk arising from these 2 activities similar in magnitude. Contrasting automobile travel and space travel helps to illustrate 3 issues pertinent to contemporary road safety policy. First, deaths during spaceflight have been entirely related to launch and landing, so dividing the number of fatalities by the enormous distances traveled by spacecraft in orbit yields a somewhat misleading expression of risk. Similarly, the risks of automobile travel vary substantially according to setting, such that an urban trip replete with merges and turns may be more dangerous than a highway trip of equal distance. Current statistics express road risks on the basis of travel distance, yet the public health implications of transportation policy decisions might be made

The American Journal of Medicine, Vol 127, No 6, June 2014 clearer if such risks were expressed per trip, per population, or by some other metric. Second, the psychology of risk perception helps explain why popular sentiment appears to devote more attention to one fatal spacecraft incident than to over 100 fatal automobile crashes.5 From the perspective of the average American, spaceflight is exotic, with a history remarkable for the deaths of celebrated individuals in catastrophes beyond their control. Compared with spaceflight disasters, automobile crashes are smaller in scale, less uniformly fatal, less likely to be filmed, and less commonly iconized. These same features (familiarity, personal control, catastrophic potential, dread, victim identifiability, and media attention, among others) also may explain why some health issues receive much more policy attention than others.6 Third, the comparison between space travel and automobile travel may help highlight the modifiable risks associated with automobile travel in America. As drivers, we may wish to reflect on how unthinkable it would be for an astronaut to operate a spacecraft under the influence of alcohol or without a safety restraint. As citizens, we may want to reconsider our current policies on speed limits, speed cameras, mandatory helmet laws, and physician warnings for medically unfit drivers. As a society, we may pause to consider how the apparent safety of our daily drive distracts us from the riskier aspects of automobile travel. John A. Staples, MD, MPHa Donald A. Redelmeier, MD, MSHSRb a

University of Washington Harborview Injury Prevention and Research Center Seattle b Division of General Internal Medicine Institute for Clinical Evaluative Sciences Sunnybrook Research Institute Evaluative Clinical Sciences University of Toronto Ontario, Canada

References 1. US Department of Transportation, National Highway Traffic Safety Administration. Fatality Analysis Reporting System (FARS) Encyclopedia. Washington, DC: National Highway Traffic Safety Administration; 2011. Available at: http://www-fars.nhtsa.dot.gov/QueryTool/ QuerySection/Report.aspx. Accessed February 6, 2012. 2. Federal Highway Administration, United States Department of Transportation. Highway statistics 2009 [Table DL-1C]; 2011. Available at: https://www.fhwa.dot.gov/policyinformation/statistics/2009/. Accessed February 24, 2014. 3. Santos A, McGuckin N, Nakamoto HY, Gray D, Liss S. Summary of Travel Trends: 2009 National Household Travel Survey [Report No.: FHWA-PL-ll-022]. Washington, DC: Federal Highway Administration, United States Department of Transportation; 2011:7,10,31,33,53. 4. US Department of Transportation, National Highway Traffic Safety Administration. Traffic Safety Facts Research Note: 2010 Motor Vehicle Crashes: Overview. Washington, DC: U.S. National Highway Traffic Safety Administration; 2012. 5. Slovic P. The Perception of Risk. London: Earthscan Publications; 2000. 6. Bangalore S, Messerli FH. Gun ownership and firearm-related deaths. Am J Med. 2013;126:873-876.

Staples, Redelmeier

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468.e1

APPENDIX

Supplementary Table 1

Mission Data for United States Crewed Space Travel, 1961-2011

Mission Name

Launch Date

Mission Elapsed Time (hours)

Distance Traveled (miles)

Crew (persons)

Fatalities (persons)

Mercury-Redstone 3 Mercury-Redstone 4 Mercury-Atlas 6 Mercury-Atlas 7 Mercury-Atlas 8 Mercury-Atlas 9 X-15 Mission 090 X-15 Mission 091 Gemini 3 Gemini 4 Gemini 5 Gemini 7 Gemini 6A Gemini 8 Gemini 9A Gemini 10 Gemini 11 Gemini 12 Apollo 7 Apollo 8 Apollo 9 Apollo 10 Apollo 11 Apollo 12 Apollo 13 Apollo 14 Apollo 15 Apollo 16 Apollo 17 Skylab 2 Skylab 3 Skylab 4 Apollo-Soyuz STS-1 STS-2 STS-3 STS-4 STS-5 STS-6 STS-7 STS-8 STS-9 STS-41-B STS-41-C STS-41-D STS-41-G STS-51-A STS-51-C STS-51-D STS-51-B STS-51-G STS-51-F STS-51-I

May 5, 1961 July 21, 1961 February 20, 1962 May 24, 1962 October 3, 1962 May 15, 1963 July 19, 1963 August 22, 1963 March 23, 1965 June 3, 1965 August 21, 1965 December 4, 1965 December 15, 1965 March 16, 1966 June 3, 1966 July 18, 1966 September 12, 1966 November 11, 1966 October 11, 1968 December 21, 1968 March 3, 1969 May 18, 1969 July 16, 1969 November 14, 1969 April 11, 1970 January 31, 1971 July 26, 1971 April 16, 1972 December 7, 1972 May 25, 1973 July 28, 1973 November 16, 1973 July 15, 1975 April 12, 1981 November 12, 1981 March 22, 1982 June 27, 1982 November 11, 1982 April 4, 1983 June 18, 1983 August 30, 1983 November 28, 1983 February 3, 1984 April 6, 1984 August 30, 1984 October 5, 1984 November 8, 1984 January 24, 1985 April 12, 1985 April 29, 1985 June 17, 1985 July 29, 1985 August 27, 1985

0.3 0.3 4.9 4.9 9.2 34.3 0.2 0.2 4.9 97.9 190.9 330.6 25.9 10.7 72.3 70.8 71.3 94.6 260.2 147.0 241.0 192.4 195.3 244.6 142.9 216.0 305.2 265.9 301.9 672.8 1427.2 2017.3 217.5 54.3 54.2 192.1 169.2 122.2 120.4 146.4 145.1 247.8 191.3 167.7 144.9 197.4 191.7 73.6 167.9 168.1 169.6 190.8 170.3

625 630 80,999 81,358 153,943 583,707 332 338 80,000 1,609,700 3,338,000 5,716,900 449,800 181,450 1,255,630 1,223,370 1,232,530 1,600,000 4,550,000 580,000 4,217,400 830,000 953,700 953,000 622,690 1,151,101 1,275,000 1,391,000 1,486,000 11,495,367 24,482,025 34,486,101 3,556,664 1,074,000 1,075,000 3,335,000 2,900,000 2,100,000 2,100,000 2,500,000 2,500,000 4,300,000 3,300,000 2,900,000 2,500,000 3,300,000 3,300,000 1,300,000 2,900,000 2,900,000 2,900,000 3,300,000 2,900,000

1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 4 4 5 5 6 5 5 6 7 5 5 7 7 7 7 5

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Notes

Source

A, B

1 1 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 3 3 3 3 3 3 3 3 3 3 3 4 4 4 5, 6, 7 8, 9 9 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10

C

A

D, E

468.e2

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Supplementary Table 1

Continued

Mission Name

Launch Date

STS-51-J STS-61-A STS-61-B STS-61-C STS-51-L STS-26 STS-27 STS-29 STS-30 STS-28 STS-34 STS-33 STS-32 STS-36 STS-31 STS-41 STS-38 STS-35 STS-37 STS-39 STS-40 STS-43 STS-48 STS-44 STS-42 STS-45 STS-49 STS-50 STS-46 STS-47 STS-52 STS-53 STS-54 STS-56 STS-55 STS-57 STS-51 STS-58 STS-61 STS-60 STS-62 STS-59 STS-65 STS-64 STS-68 STS-66 STS-63 STS-67 STS-71 STS-70 STS-69 STS-73 STS-74 STS-72 STS-76 STS-77 STS-78

October 3, 1985 October 30, 1985 November 26, 1985 January 12, 1986 January 28, 1986 September 29, 1988 December 2, 1988 March 13, 1989 May 4, 1989 August 8, 1989 October 18, 1989 November 22, 1989 January 9, 1990 February 28, 1990 April 24, 1990 October 6, 1990 November 15, 1990 December 2, 1990 April 5, 1991 April 28, 1991 June 5, 1991 August 2, 1991 September 12, 1991 November 24, 1991 January 22, 1992 March 24, 1992 May 7, 1992 June 25, 1992 July 31, 1992 September 12, 1992 October 22, 1992 December 2, 1992 January 13, 1993 April 8, 1993 April 26, 1993 June 21, 1993 September 12, 1993 October 18, 1993 December 2, 1993 February 3, 1994 March 4, 1994 April 9, 1994 July 8, 1994 September 9, 1994 September 30, 1994 November 3, 1994 February 3, 1995 March 2, 1995 June 27, 1995 July 13, 1995 September 7, 1995 October 20, 1995 November 12, 1995 January 11, 1996 March 22, 1996 May 19, 1996 June 20, 1996

Mission Elapsed Time (hours) 97.7 168.7 165.1 146.1 0.0 97.0 105.1 119.6 96.9 121.0 119.7 120.1 261.0 106.3 121.3 98.2 117.9 215.1 143.5 199.4 218.2 213.4 128.5 166.8 193.2 214.2 213.3 331.7 191.3 190.7 236.9 175.3 143.6 222.1 239.7 239.7 236.2 336.2 260.0 199.2 335.3 269.8 353.9 262.8 269.8 262.6 198.5 399.1 235.4 214.3 260.5 381.9 196.5 214.0 221.3 240.7 405.8

Distance Traveled (miles) 1,700,000 2,956,640 2,800,000 2,500,000 18 1,700,000 1,800,000 2,000,000 1,700,000 2,100,000 2,000,000 2,100,000 4,500,000 1,900,000 2,100,000 1,700,000 2,000,000 3,700,000 2,500,000 3,500,000 3,800,000 3,700,000 2,200,000 2,900,000 2,900,000 3,200,000 3,700,000 5,800,000 3,300,000 3,300,000 4,100,000 3,034,518 2,505,103 3,900,000 4,200,000 4,100,000 4,100,000 5,800,000 4,400,000 3,400,000 5,800,000 4,700,000 6,100,000 4,500,000 4,700,000 4,500,000 3,000,000 6,900,000 4,100,000 3,700,000 4,500,000 6,600,000 3,400,000 3,700,000 3,800,000 4,100,000 7,000,000

Crew (persons)

Fatalities (persons)

5 8 7 7 7 5 5 5 5 5 5 5 5 5 5 5 5 7 5 7 7 5 5 6 7 7 7 7 7 7 6 5 5 5 7 6 5 7 7 6 5 6 7 6 6 6 6 7 7.5 5 5 7 5 6 5.5 6 7

0 0 0 0 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Notes F

A, G

H I

J

J

Source 10 8 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10

Staples, Redelmeier

Fatality Risks on the Road and in Space

Supplementary Table 1

468.e3

Continued

Mission Name

Launch Date

STS-79 STS-80 STS-81 STS-82 STS-83 STS-84 STS-94 STS-85 STS-86 STS-87 STS-89 STS-90 STS-91 STS-95 STS-88 STS-96 STS-93 STS-103 STS-99 STS-101 STS-106 STS-92 STS-97 STS-98 STS-102 STS-100 STS-104 STS-105 STS-108 STS-109 STS-110 STS-111 STS-112 STS-113 STS-107 STS-114 STS-121 STS-115 STS-116 STS-117 STS-118 STS-120 STS-122 STS-123 STS-124 STS-126 STS-119 STS-125 STS-127 STS-128 STS-129 STS-130 STS-131 STS-132 STS-133 STS-134 STS-135

September 16, 1996 November 19, 1996 January 12, 1997 February 11, 1997 April 4, 1997 May 15, 1997 July 1, 1997 August 7, 1997 September 25, 1997 November 19, 1997 January 22, 1998 April 17, 1998 June 2, 1998 October 29, 1998 December 4, 1998 May 27, 1999 July 23, 1999 December 19, 1999 February 11, 2000 May 19, 2000 September 8, 2000 October 11, 2000 November 30, 2000 February 7, 2001 March 8, 2001 April 19, 2001 July 12, 2001 August 10, 2001 December 5, 2001 March 1, 2002 April 8, 2002 June 5, 2002 October 7, 2002 November 23, 2002 January 16, 2003 July 26, 2005 July 4, 2006 September 9, 2006 December 9, 2006 June 8, 2007 August 8, 2007 October 23, 2007 February 7, 2008 March 11, 2008 May 31, 2008 November 14, 2008 March 15, 2009 May 11, 2009 July 15, 2009 August 28, 2009 November 16, 2009 February 8, 2010 April 5, 2010 May 14, 2010 February 24, 2011 May 16, 2011 July 8, 2011

Mission Elapsed Time (hours) 243.3 423.9 244.9 239.6 95.2 239.3 376.7 283.3 259.3 376.6 211.8 381.8 235.9 235.9 283.3 235.2 118.8 191.2 269.6 236.2 283.2 309.7 260.0 308.3 307.8 276.9 306.6 283.6 283.9 262.2 259.7 332.6 260.0 330.8 382.4 333.5 306.6 283.1 308.8 332.2 305.9 362.4 306.4 378.2 330.2 380.5 307.5 309.6 376.8 332.9 259.3 330.1 362.8 282.5 307.1 377.6 306.5

Distance Traveled (miles) 3,900,000 7,000,000 4,100,000 4,100,000 1,500,000 3,600,000 6,200,000 4,700,000 4,429,815 6,500,000 3,676,402 6,500,000 3,800,000 3,600,000 4,700,000 3,800,000 1,800,000 3,200,000 4,100,000 4,100,000 4,900,000 4,900,000 4,500,000 5,300,000 5,300,000 4,900,000 5,300,000 4,300,000 4,800,000 3,900,000 4,500,000 5,800,000 4,500,000 5,700,000 6,000,000 5,800,000 5,300,000 4,900,000 5,300,000 5,800,000 5,300,000 6,250,000 5,300,000 6,600,000 5,700,000 6,600,000 5,300,000 5,276,000 6,500,000 5,700,000 4,500,000 5,700,000 6,200,000 4,800,000 5,300,000 6,500,000 5,200,000

Crew (persons)

Fatalities (persons)

6 5 6 7 7 7 7 6 7 6 7 7 6.5 7 6 7 5 7 6 7 7 7 5 5 7 7 5 7 7 7 7 7 6 7 7 7 6.5 6 7 7 7 7 7 7 7 7 7 7 7 7 6.5 6 7 6 6 6 4

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Notes

K L J

D, M J

J

Source 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 11 10 10 10 10 12 13, 14 15, 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

468.e4 Notes for Supplementary Table 1 A

B

C

D

E

F

G

H

I

J

The American Journal of Medicine, Vol 127, No 6, June 2014 Mission Data for United States Crewed Space Travel, 1961-2011

INCLUSION AND EXCLUSION CRITERIA: All crewed spaceflight missions launched by the United States of America (including those launched by the National Aeronautics and Space Administration [NASA] or the United States Air Force [USAF]) with an intended or achieved maximum altitude exceeding 100 kilometers (in keeping with the Fédération Aéronautique Internationale [FAI] criteria for space flight [Source 32]) were included in the analysis. Deaths occurring during training were excluded if they did not occur while on a flight with an intended or achieved maximum altitude exceeding 100 km. Deaths were also excluded if they resulted from causes unrelated to spaceflight missions. Following these criteria, mission STS-51-L (the fatal Challenger disaster of 1986) was included in the analysis, as it was launched with an intended maximum altitude exceeding 100 km. The death of Michael J. Adams (occurring during an X-15 flight to a maximum altitude of 50.4 miles) was excluded, as neither the intended nor the achieved maximum altitude met the FAI criteria. The fatal Apollo 1 launch pad test fire (in which Virgil I. Grissom, Edward H. White, and Roger B. Chaffee lost their lives) was excluded from the analysis, as it occurred during a training exercise that occurred 25 days before the target launch date. The deaths of the following crew or potential crew were also excluded from the analysis as they did not occur while on a spaceflight mission: Theodore C. Freeman, Elliot M. See, Charles Bassett, Clifton C. Williams, Robert H. Lawrence, and S. David Griggs (died in training airplane crashes); Edward G. Givens (died as a result of an automobile crash); M. L. "Sonny" Carter (died in a commercial airplane crash); Patricia Hilliard Robertson, Stephen D. Thorne (died as a result of private airplane crashes); Charles Lacy Veach (died "following a lengthy illness") [Sources 33, 34]. In accordance with study criteria, the analysis includes only those spaceflight missions undertaken by the United States of America (including those to Skylab, Mir, and the International Space Station). Spaceflight missions undertaken by other nations or by private entities (such as those occurring under the Vostok, Voshkhod, Soyuz, TSK, Shenzhou, and Tier One programmes) were excluded from the analysis. Reported distance estimates are displayed in standard decimal notation (rather than scientific notation) to facilitate a more intuitive understanding of magnitude. All mission distances were reported to a precision of at least two significant figures, with the exception of mission STS-107, for which source documents report that it traveled “more than six million miles”. For the purposes of this analysis, we assume that this is also precise to two significant figures. The Apollo-Soyuz Test Project (ASTP) was a joint effort by the United States of America and the Union of Soviet Socialist Republics (USSR). In keeping with our inclusion criteria, the Apollo portion of the ASTP (launched by the United States) is included in the analysis, while the Soyuz portion of the ASTP (launched by the Soviet Union) is not. The approximate distance traveled by Apollo on the Apollo-Soyuz Test Project mission (Apollo portion) was not listed in sources 6, 7, or 8. Mission distance was therefore estimated using figures from the Apollo-Soyuz Mission Evaluation Report (Source 7). The arithmetic mean of the apogee (223.5 km) and perigee (222.8 km) at the time of the first Apollo-Soyuz docking was used to estimate an average mission altitude (223.2 km) for the Apollo spacecraft. This was added to the equatorial radius of the Earth (6378.2 km) to estimate the radius of the Apollo orbit (6601.4 km), which was assumed to be circular for the purposes of these calculations. From this, the circumferential distance traveled by Apollo per revolution around the Earth was estimated to be (Pi)*(2) *(orbital radius) ¼ (3.14159265)*(2)*(6601.4 km) ¼ 41,478 km. Assuming that liftoff and splashdown trajectories influenced total mission distance by a negligible amount, the estimated total mission distance after Apollo’s 138 revolutions would be 5,723,896 km (3,556,664 miles). Total mission distance was estimated using data from the NASA Historical Data Books, Volume 3 (Source 8, p325) and the assumptions and equations listed in Note E above. With a listed orbital altitude of 383.4 km and 112 completed revolutions, the estimated total mission distance for mission STS-61-A is (6378.2 km þ 383.4 km)*(2)*(Pi)*(112 circumferential revolutions) ¼ 4,758,251 km (2,956,640 miles). The Space Shuttle Challenger disaster resulted in the deaths of Commander Francis R. Scobee, Pilot Michael J. Smith, Mission Specialist Judith A. Resnik, Mission Specialist Ellison S. Onizuka, Mission Specialist Ronald E. McNair, Payload Specialist Gregory B. Jarvis, and Payload Specialist Sharon Christa McAuliffe. Total mission distance was estimated using data from the Space Shuttle Mission Information webpage (Source 10) and the assumptions and equations listed in Note E above. With a listed orbital altitude of 174 nautical miles (322 km) and 116 Earth revolutions, the estimated total mission distance for Mission STS-53 is (6378.2 km þ 322 km)*(2)*(Pi)*(116 circumferential revolutions) ¼ 4,883,583 km (3,034,518 miles). Total mission distance was estimated using data from the Space Shuttle Mission Information webpage (Source 10) and the assumptions and equations listed in Note E above. With a listed orbital altitude of 165 nautical miles (306 km) and 96 Earth revolutions, the estimated total mission distance for Mission STS-54 is (6378.2 km þ 306 km)*(2)*(Pi)*(96 circumferential revolutions) ¼ 4,031,573 km (2,505,103 miles). A mission that left Earth with 8 crew members, docked with a space station, and returned to Earth with 7 crew members (leaving one behind to reside on the space station) is designated as having 7.5 “crew-equivalents” for the duration of the mission. Thus, crew members being shuttled from Earth to a space station are considered to contribute exactly half of the at-risk person-miles of a crew member aboard for both the outbound and returning journeys of the mission. Distance traveled by crew residing in a space station was excluded from the at-risk ‘distance traveled’ denominator except during their transport to or from the space station.

Staples, Redelmeier

Fatality Risks on the Road and in Space

Notes for Supplementary Table 1 K

L

M

468.e5

Continued

Total mission distance was estimated using data from the Space Shuttle Mission Information webpage (Source 10) and the assumptions and equations listed in Note E above. With a listed orbital altitude of 184 statute miles (296 km) and 170 Earth revolutions, the estimated total mission distance for Mission STS-86 is (6378.2 km þ 296 km)*(2)*(Pi)*(170 circumferential revolutions) ¼ 7,129,097 km (4,429,815 miles). Total mission distance was estimated using data from the Space Shuttle Mission Information webpage (Source 10) and the assumptions and equations listed in Note E above. With a listed orbital altitude of 214 nautical miles (396.3 km) and 139 Earth revolutions, the estimated total mission distance for Mission STS-89 is (6378.2 km þ 396.3 km)*(2)*(Pi)*(139 circumferential revolutions) ¼ 5,916,596 km (3,676,402 miles). The Space Shuttle Columbia disaster resulted in the deaths of Commander Rick D. Husband, Pilot William C. McCool, Payload Commander Michael P. Anderson, Payload Specialist Ilan Ramon, Mission Specialist Kalpana Chawla, Mission Specialist David M. Brown, and Mission Specialist Laurel B. Clark.

468.e6 Sources for Supplementary Table 1 1

2 3

4

5

6

7

8

9

10 11

12

13

14

15

16

17 18 19 20 21 22

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Ezell LN. NASA Historical Data Books Volume 2: 1958-1968 (NASA Special Publication 4012) [Internet]. Washington, D.C.: National Aeronautics and Space Administration; 1976. p 143-168 [updated 27 March 2009; cited 30 January 2012]. Available from: http:// history.nasa.gov/SP-4012/cover.html Goodwin R. X-15: the NASA mission reports, incorporating files from the USAF. Burlington, Ontario: Apogee Books; 2000. p 365. Orloff RW. Apollo by the Numbers: A Statistical Reference (NASA Special Publication 4029) [Internet]. Washington, D.C.: NASA History Division, Office of Policy and Plans, National Aeronautics and Space Administration; 2000 [updated 27 September 2005; cited 30 January 2012]. Available from: http://history.nasa.gov/SP-4029/SP-4029.htm Benson CD and Compton BD. Living and Working in Space: A History of Skylab (NASA Special Publication SP-4208) [Internet]. Washington, D.C.: National Aeronautics and Space Administration; 1983. p373. [updated 6 August 2004; cited 30 January 2012]. Available from: http://history.nasa.gov/SP-4208/app.a.htm Ezell EC and Ezell LN. The Partnership: A History of the Apollo-Soyuz Test Project (NASA Special Publication 4209) [Internet]. Washington, D.C.: National Aeronautics and Space Administration; 1978 [updated 18 November 2005; cited 30 January 2012]. Available from: http://history.nasa.gov/SP-4209/toc.htm Apollo-Soyuz Test Project Historical Documents [Internet]. Washington, D.C.: NASA History Program Office, National Aeronautics and Space Administration; 2010 [updated 16 March 2010; cited 3 February 2012]. Available from: http://history.nasa.gov/astp/gallery. html Apollo-Soyuz Mission Evaluation Report (Report Number JSC-10607) [Internet]. Houston, TX: Johnson Space Center, National Aeronautics and Space Administration; 1975 [updated 14 June 2011; cited 2 February 2012]. pp 3-5, 3-7, B-30. Available from: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19760023154_1976023154.pdf Rumerman JA. NASA Historical Data Books Volume V: NASA Launch Systems, Space Transportation, Human Spaceflight, and Space Science, 1979-1988 (NASA Special Publication 4012) [Internet]. Washington, D.C.: National Aeronautics and Space Administration; 1999. pp 3-5, 3-7 [updated 15 October 2010; cited 30 January 2012]. Available from: http://history.nasa.gov/SP-4012/cover.html NASA Space Shuttle Launch Archive [Internet]. Cape Canaveral, FL: Kennedy Space Center, National Aeronautics and Space Administration; 2003 [updated 1 February 2003; cited 30 January 2012]. Available from: http://science.ksc.nasa.gov/shuttle/ missions/missions.html Space Shuttle Mission Information [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2001 [updated 29 August 2011; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/index.html Columbia Accident Investigation Board Final Report, Volume 1 [Internet]. Washington, D.C.: Columbia Accident Investigation Board; August 2003. pp 6, 39. [updated 26 August 2003; cited 12 Dec 2011]. Available from: http://spaceflight.nasa.gov/shuttle/ archives/sts-107/investigation/index.html NASA News: STS-117 MCC Status Report #30 [Internet]. Houston, TX: National Aeronautics and Space Administration Mission Control Center; 2007. [updated 22 June 2007; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/ shuttlemissions/sts117/news/STS-117-30.html NASA News: STS-118 MCC Status Report #27 [Internet]. Houston, TX: National Aeronautics and Space Administration Mission Control Center; 2007 [updated 21 August 2007; cited 30 January 2012] Available from: http://www.nasa.gov/mission_pages/shuttle/ shuttlemissions/sts118/news/STS-118-27.html STS-118: Launch and Landing [Internet]. Washington, D.C.: National Aeronautics and Space Administration; 2007. [updated 23 November 2007; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts118/ launch/index.html NASA News: STS-120 MCC Status Report #32 [Internet]. Houston, TX: National Aeronautics and Space Administration Mission Control Center; 2007 [updated 7 November 2007; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/ shuttlemissions/sts120/news/STS-120-32.html STS-120: Launch and Landing [Internet]. Washington, D.C.: National Aeronautics and Space Administration; 2007 [updated 17 December 2007; 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts120/launch/ index.html STS-122: Launch [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2008 [updated 25 November 2008; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts122/launch/index.html STS-123 [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2008 [updated 4 April 2008; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts123/launch/index.html STS-124: Launch [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2008 [updated 27 June 2008; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts124/launch/index.html STS-126: Launch [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2008 [updated 19 December 2008; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts126/launch/index.html STS-119: Launch [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2009 [updated 4 May 2009; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts119/launch/index.html STS-125: Launch [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2009 [updated 25 June 2009; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts125/launch/index.html

Staples, Redelmeier

Fatality Risks on the Road and in Space

Sources for Supplementary Table 1 23 24 25 26 27 28 29 30 31 32

33 34

468.e7

Continued

STS-127: Launch [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2009 [updated 10 August 2009; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts127/launch/index.html STS-128: Launch [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2010 [updated 20 January 2010; 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts128/launch/index.html STS-129: Launch [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2010 [updated 23 February 2010; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts129/launch/index.html STS-130: Launch [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2010 [updated 30 March, 2010; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts130/launch/index.html STS-131: Launch [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2010 [updated 28 April 2010; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts131/launch/index.html STS-132: Launch [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2010 [updated 4 June 2010; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts132/launch/index.html STS-133: Launch [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2011 [updated 15 March 2011; 30 January 2012] Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/launch/index.html STS-134 Mission [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2011 [updated 10 June 2011; 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/launch/index.html STS-135: Launch [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c2011 [updated 27 July 2011; cited 30 January 2012]. Available from: http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/launch/index.html Fédération Aéronautique Internationale. FAI Sporting Code Section 8 [Internet]. Lausanne, Switzerland: Fédération Aéronautique Internationale; 2009. p 6, Line 2.18.1. [updated 11 September 2009; cited 7 February 2012]. Available from: http://www.fai.org/ fai-documents Astronaut Fact Book (NP-2005-01-001JSC). Washington, DC.: National Aeronautics and Space Administration; January 2005. p57-61. [cited 8 February 2012]. Available from: http://spaceflight.nasa.gov/spacenews/factsheets/pdfs/astro.pdf Stafford LE. First African-American astronaut finally acknowledged [Internet]. Washington, D.C.: American Forces Press Service, U.S. Department of Defense; 5 February 1998 [updated 5 February 1998; cited 15 February 2012]. Available from: http://www.defense. gov/news/newsarticle.aspx?id¼43073

468.e8 Supplementary Table 2

The American Journal of Medicine, Vol 127, No 6, June 2014 United States Space Travel, 1961-2011 (50 years)

Basic Data Average trip distance (miles) Average trip duration (hours) Average trip velocity (miles / hour) Average vehicle occupancy (persons) Exposure Indices Total number of spaceflight vehicle trips (count) Total distance traveled (vehicle-miles) Total distance traveled (person-miles) Total travel time (hours) Total travel time (person-hours) Travel Fatalities Fatal spaceflight incidents (count) Spaceflight fatalities (persons) Spaceflight fatalities per 100,000 population (persons) Demographics Average U.S. population, 1961-2011 (persons) Average age at death among fatalities (years) Proportion male among fatalities (%) Proportion white among fatalities (%) Analytic Comparisons Risk of fatal spaceflight incident (per vehicle-trip) Lifetime risk of death due to spaceflight (%) Risk of death (per 100,000 person-hours) Risk of death (per 100 million vehicle-miles) Risk of death (per 100 million person-miles)

Value

Notes

Sources

3,892,452 237.1 15,936 5.3

A, B C D E

1 2, 3 1, 2, 3 1

168 653,931,855 3,714,261,705 39,836 222,643

F G H

1 1 1 2, 3 1

2 14 0.0057

I

1 1 4, 5, 6

244,007,521 42.4 71.4 71.4

J K K K, L

4, 5, 6 7 7 7, 8

1.2x102 (0.21x102 4.7x102) 3.6 (2.0 - 6.0) 6.3 (3.6 - 10.8) 2.1 (1.2 - 3.7) 0.38 (0.22 - 0.65)

M N O, H P Q, F

1 2, 3 1 1 1

Staples, Redelmeier

Fatality Risks on the Road and in Space

Notes for Supplementary Table 2

B

C D E

F

G H

I J K

L

M N

O

P Q

United States Space Travel, 1961-2011 (50 years)

(Total distance traveled of 653,931,855 vehicle miles) / (168 spaceflight missions in total) ¼ Average trip distance of 3,892,452 vehicle-miles The values reported in this table are displayed in standard decimal notation (rather than in scientific notation) to facilitate a more intuitive understanding of their magnitude. Additionally, although using only two significant figures would better represent the precision of the values discovered in source documents, we have presented the full figures here to allow readers the opportunity to replicate our calculations. (Aggregate mission elapsed time of 39,836 hours) / (168 spaceflight missions in total) ¼ Average trip duration of 237.1 hours (Total trip distance for a given mission) / (Mission elapsed time for a given mission) ¼ Average velocity for a given mission The arithmetic mean of these mission average velocities was calculated to be 15,936 miles/hour. For a particular mission, an individual aboard the spaceflight vehicle for the full mission generates one ’crew-equivalent’, while an individual traveling only from Earth to a space station (but not back) generates 0.5 crew-equivalents for that mission. (Sum of 890.5 crew-equivalents across all missions) / (168 spaceflight missions in total) ¼ Average vehicle occupancy of 5.3 persons Person-distance traveled per mission was calculated by multiplying the vehicle-distance traveled by the number of crew-equivalents. Total person-distance traveled for all missions is the sum of these products across all missions. See Note H from Supplementary Table I: Mission Data for United States Crewed Space Travel, 1961-2011. Mission Elapsed Time for each mission was obtained directly from the cited sources where possible. Otherwise, it was calculated by subtracting launch time and date from landing time and date. Spaceflight person-time per mission was calculated by multiplying each Mission Elapsed Time by the number of crew-equivalents. Total spaceflight person-time for all missions is the sum of these products across all missions. See Note H from Supplementary Table I: Mission Data for United States Crewed Space Travel, 1961-2011. (14 deaths due to spaceflight) / (Average U.S. population of 244,007,521 during the 1961-2011 period) ¼ 0.0057 deaths per 100,000 population The average population of the United States of America during the period of U.S. crewed spaceflight (1961-2011) was estimated by taking the arithmetic mean of annual U.S. population estimates from 1961-2011. For each of the 14 spaceflight-related fatalities, the age at date of death was calculated by subtracting a crew member’s date of birth from their date of death. The arithmetic mean age at death was 42.4 years. Ten of the fourteen spaceflight fatalities were male. Ten of the fourteen spaceflight fatalities were white. ’White race’ was defined according to the U.S. Office of Management and Budget’s (OMB) 1997 Revisions to the Standards for the Classification of Federal Data on Race and Ethnicity: “a person having origins in any of the original peoples of Europe, the Middle East, or North Africa.” (Source 8) (2 fatal spaceflight incidents) / (168 spaceflight missions) ¼ 1.2 x 10 (-2) risk of fatal spaceflight incident per vehicle-trip. Binomial two-sided 95% confidence interval calculated by the method of Fleiss (Source 9) indicated in parentheses. (14 deaths due to spaceflight) / (393 individuals have been crew on a U.S. spaceflight) ¼ For crew on U.S. spaceflights, there is a 3.6% lifetime risk of death due to spaceflight. A list of all U.S. spaceflight crew (astronauts, cosmonauts, mission specialists, and payload specialists regardless of nationality) was compiled using the U.S. Human Spaceflight Log and crew lists from Space Shuttle missions between 2003 and 2011. Binomial twosided 95% confidence interval calculated by the method of Fleiss (Source 9) indicated in parentheses. (14 deaths due to spaceflight) / (Aggregate mission elapsed time of 222,643 person-hours of travel) ¼ 6.3 deaths due to spaceflight per 100, 000 person-hours of travel Binomial 2-sided 95% confidence interval calculated by the method of Fleiss (Source 9) indicated in parentheses. (14 deaths due to spaceflight) / (653,931,855 vehicle-miles of spaceflight) ¼ 2.1 deaths per 100 million vehicle-miles of travel Binomial 2-sided 95% confidence interval calculated by the method of Fleiss (Source 9) indicated in parentheses. (14 deaths due to spaceflight) / (3,714,261,705 person-miles of spaceflight) ¼ 0.38 deaths per 100 million person-miles of travel. Binomial 2-sided 95% confidence interval calculated by the method of Fleiss (Source 9) indicated in parentheses. ˇ

A

468.e9

468.e10 Sources for Supplementary Table 2 1 2 3 4

5

6

7 8

9

The American Journal of Medicine, Vol 127, No 6, June 2014 United States Space Travel, 1961-2011 (50 years)

See Supplementary Table 1: Mission Data for United States Crewed Space Travel, 1961-2011 in this Supplemental Appendix. Astronaut Fact Book (NP-2005-01-001JSC). Washington, DC.: National Aeronautics and Space Administration; January 2005. p77-83. [cited 8 February 2012]. Available from: http://spaceflight.nasa.gov/spacenews/factsheets/pdfs/astro.pdf See Sources 10 to 31 from Supplementary Table 1: Mission Data for United States Crewed Space Travel, 1961-2011 in this Supplemental Appendix. Historical National Population Estimates: July 1, 1900 to July 1, 1999 [Internet]. Washington, D.C.: Population Estimates Program, Population Division, U.S. Census Bureau; 2000 [revised 28 June 2000; cited 6 February 2012]. Available from: http://www.census. gov/popest/data/national/totals/pre-1980/tables/popclockest.txt Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2000 to July 1, 2009 (NST-EST2009-01). Washington, D.C.: Population Division, U.S. Census Bureau; 2009 [released December 2009; cited 6 February 2012]. Available from: http://www.census.gov/popest/data/historical/2000s/vintage_2009/index.html Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2010 to July 1, 2011 (NST-EST2011-01). Washington, D.C.: Population Division, U.S. Census Bureau; 2011 [released December 2011; cited 6 February 2012]. Available from: http://www.census.gov/popest/data/national/totals/2011/index.html Astronaut biographies [Internet]. Washington, D.C.: National Aeronautics and Space Administration; c1966-2012 [updated 17 June 2011; cited 3 February 2012]. Available from: http://www.jsc.nasa.gov/Bios/ Hixson L, Hepler BB, Kim MO. The White Population: 2010 (C2010BR-05). 2010 Census Briefs. Washington, D.C.: U.S. Census Bureau, Economics and Statistics Administration, U.S. Department of Commerce; Issued September 2011. p 2 [cited 6 February 2012]. Available from: http://www.census.gov/prod/2001pubs/c2kbr01-4.pdf Fleiss JL, Levin B, Paik MC. Statistical methods for rates and proportions. 3rd ed. Hoboken: John Wiley & Sons, Inc.; 2003. p28.

Staples, Redelmeier

Fatality Risks on the Road and in Space

Supplementary Table 3

468.e11

United States Automobile Travel (1 Year)* Value

Basic Data Average trip distance (miles) Average trip duration (minutes) Average trip velocity (miles / hour) Average vehicle occupancy per trip, all purposes (persons) Average daily time spent in an automobile as a driver (minutes) Average daily time spent in an automobile as a driver or passenger (minutes) Average yearly time spent in an automobile as a driver (hours) Average yearly time spent in an automobile as a driver or passenger (hours) Average daily vehicle trips per driver (count) Exposure Indices Total number of household vehicle trips (count) Total distance traveled (vehicle-miles) Total distance traveled (person-miles) Total travel time (person-hours) Travel Fatalities Fatal automobile incidents (count) Automobile fatalities (persons) Automobile fatalities per 100,000 population (persons) U.S. driving-aged [16 and older] population (persons) Licensed drivers (persons) Licensed drivers per 1000 driving-aged population (persons) U.S. adult [18 and older] population (persons) Licensed adult [18 and older] drivers (persons) Licensed adult drivers per 1000 adult population (persons) Life expectancy at birth in 2009 (years) Average age at death among fatalities (years) Proportion male among fatalities (%) Proportion white among fatalities (%) Analytic Comparisons Risk of fatal automobile crash (per vehicle-trip) Lifetime risk of death due to automobile crash (%) Risk of death (per 100,000 person-hours) Risk of death (per 100 million vehicle-miles) Risk of death (per 100 million person-miles) *‘1 year’ denotes 2010 where possible and 2009 otherwise.

Notes

Sources

A B C D E

1 1 1 1 1 1

F G

1 (p. 31) 1 (p. 31)

-

1 (p. 10)

H, I J K L

1 2 2 1

30,196 32,885 11.01 240,989,961 209,618,000 870 234,564,071 205,781,457 877 78.2 41.6 70.2 74.1

M M M N O P Q

2 (p. 2 (p. 3 (p. 4 3 (p. 4 5 6 5, 6 7 3 (p. 3 (p. 8

3) 1) i)

1.3x107(1.3x107-1.3x107) 0.86 (0.81 - 0.92) 0.028 (0.027 - 0.028) 1.1 (1.1 - 1.1) 0.66 (0.65 - 0.66)

R S T U V

2 3 2 2 2

1), 1 (p. 7) i), 7 (p. 3) 1), 1 (pp. 31, 33) 1) 1), 1 (p. 33)

9.72 18.6 31.4 1.67 56.1 60 341 365 3.02 233,849,000,000 2,999,974,000,000 5,009,956,580,000 119,446,134,085

(p. 10) (pp. 10, 31) (pp. 7, 10, 31, 33, 53) (p. 33) (p. 31) (p. 30)

(p. (p. (p. (p.

(p. (p. (p. (p. (p.

7) 1) 1), 1 (p. 33) 31, 33), 3 (p. i)

i)

88) 88)

468.e12

The American Journal of Medicine, Vol 127, No 6, June 2014

Notes for Supplementary Table 3

B C D E F G H

I

J

K L

M N O

P Q

R S

T

U

V

United States Automobile Travel (1 year)

Average trip length was calculated in Source 1 using only those trips for which mileage was available. It appears to exclude trips taken in taxis, buses, streetcars, and school buses. (Drivers spend an average of 56.09 minutes per day in an automobile) / (Drivers take 3.02 trips on the average day) ¼ The average trip takes 18.6 minutes. (The average vehicle trip distance is 9.72 miles) / (Average trip time is 18.6 minutes) ¼ The average trip velocity is 31.4 miles per hour. The average vehicle occupancy reported here is miles-weighted (i.e. reported trip vehicle occupancy weighted by trip distance) and was calculated by NHTSA. The total time spent in a vehicle as a driver or a passenger is “about an hour overall” (Source 1, pp30, Figure 5 and accompanying text). An exact figure is not reported. (The average driver spends 56.09 minutes per day in an automobile) * (365 days per year) ¼ The average driver spends 341 hours in an automobile per year. (The average time per day spent in an automobile as a driver or passenger is ’about an hour’) ¼ The average American household member spends 365 hours in an automobile per year. This is the number of one-way trips taken by privately owned vehicles, regardless of the number of vehicle occupants (ie, 2 people traveling from home to a restaurant is considered one trip). It includes trips taken as a part of work. It does not include trips taken in buses, streetcars, taxis or school buses (see Source 3, pp 3, A-3). The values reported in this table are displayed in standard decimal notation (rather than scientific notation) to allow a more intuitive understanding of their magnitude. Values reported under the ’Analytic Comparisons’ heading are limited to two significant figures to better reflect the precision in these derived values. Originally from the Federal Highway Administration (FHWA). The FHWA “. estimates national trends by using State reported Highway Performance and Monitoring System (HPMS) data, fuel consumption data (MF-21 and MF-27), vehicle registration data (MV-1, MV-9, and MV-10), other data such as the R.L. Polk vehicle data, and a host of modeling techniques” (Source 6). (2,999,974,000,000 vehicle-miles of automobile travel in 2010) * (Average vehicle occupancy of 1.67 persons) ¼ 5,009,956,580,000 person-miles of automobile travel in 2010. (The average driver spends 56.09 minutes per day driving) * (365 days per year)* (209,618,000 licensed drivers in the U.S. in 2009) ¼ 71,524,631,188 vehicle-hours of driving per year by all drivers. Multiplied by an average vehicle occupancy of 1.67 persons, this yields 119,446,134,085 person-hours of travel in 2009. These values relate to police-reported fatal motor vehicle crashes. (209,618,386 licensed drivers in 2009) - [(409,526 drivers 74’, 79.5 years was arbitrarily designated the midpoint age. Methodology assumes midpoint age for a category approximates category mean age. (10,070 female fatalities in 2009) / (33,808 total fatalities in 2009) ¼ 29.7% of 2009 motor vehicle crash fatalities were female. Demographics for 2010 fatalities were not available at the time of article submission. The interactive portion of the NHTSA FARS Encyclopedia website (Source 5, ’Query FARS Data’ tab; Year ¼ 2009; State ¼ All; Injury Severity ¼ Fatal; Race ¼ All) was used to determine that 25,055 of 33,883 fatalities in 2009 were reported to be white. The minor inconsistency between total number of fatalities reported here (33,883) and that reported in Source 2 (33,808) was ignored. (25,055 police-reported fatalities reported to be white) / (33,883 total police-reported fatalities) ¼ 74% of fatalities were reported to be white (30,196 police-reported fatal motor vehicle crashes) / (233,849,000,000 household vehicle trips) ¼ The risk of fatal crash per vehicletrip is 1.3x10 (-7). (11.01 police-reported fatalities per 100,000 population) * (In 2009, life expectancy from birth is 78.2 years) ¼ Lifetime risk of motor vehicle crash death is 0.86%. Methodology assumes that the annual risk of motor vehicle crash death is identical for every year of life. Binomial two-sided 95% confidence interval calculated by the method of Fleiss (Source 10) indicated in parentheses. (32,885 police-reported motor vehicle crash fatalities) / [(56.09 minutes/day per driver in a motor vehicle) * (365 days/year) * (209,618,000 licensed drivers) * (Average occupancy of 1.67 persons per vehicle)] ¼ 0.028 deaths per 100,000 person-hours of travel. Binomial 2-sided 95% confidence interval calculated by the method of Fleiss (Source 10) indicated in parentheses. (32,885 police-reported motor vehicle crash fatalities) / (2.999 billion vehicle miles traveled) ¼ 1.10 deaths per 100 million vehicle-miles of travel. Binomial 2-sided 95% confidence interval calculated by the method of Fleiss (Source 10) indicated in parentheses. (32,885 police-reported motor vehicle crash fatalities) / [(3.000 billion vehicle miles traveled) * (1.67 persons per vehicle on average) ¼ 0.66 deaths per 100 million person-miles of travel. Binomial 2-sided 95% confidence interval calculated by the method of Fleiss (Source 10) indicated in parentheses. ˇ

A

Staples, Redelmeier

Fatality Risks on the Road and in Space

Sources for Supplementary Table 3 1 2

3 4

5

6

7 8 9

10

468.e13

United States Automobile Travel (1 Year)

Summary of Travel Trends: 2009 National Household Travel Survey [Internet]. Washington, D.C.: U.S. Department of Transportation, Federal Highway Administration; 2011 [cited 19 January 2012]. Available from: http://nhts.ornl.gov/publications.shtml Traffic Safety Facts Research Note - 2010 Motor Vehicle Crashes: Overview [Internet]. Washington, D.C.: U.S. National Highway Traffic Safety Administration; 2012 [revised February 2012; cited 3 April 2012]. Available from: http://www.nhtsa.gov/AboutþNHTSA/ PressþReleases/2012/U.S.þTransportationþSecretaryþLaHoodþAnnouncesþLowestþLevelþOfþAnnualþTrafficþFatalitiesþInþ MoreþThanþSixþDecades Traffic Safety Facts 2009 [Internet]. Washington, D.C.: U.S. National Highway Traffic Safety Administration; 2011 [cited 19 January 2012]. Available from: http://www-nrd.nhtsa.dot.gov/cats/listpublications.aspx?Id¼E&ShowBy¼DocType Table DL-1C: Licensed Drivers by Sex and Ratio to Population - 2009. In: Highway Statistics 2009 [Internet]. Washington, D.C.: United States Department of Transportation, Federal Highway Administration; February 2011 [updated 3 January 2012; cited 26 January 2012]. Available from: www.fhwa.dot.gov/policyinformation/statistics/2009/dl1c.cfm Howden LM and Meyer JA. Age and Sex Composition: 2010. 2010 Census Briefs [Internet]. Washington, D.C.: United States Census Bureau, U.S. Department of Commerce, Economics and Statistics Administration; May 2011 [cited 29 March 2012]. Available from www.census.gov/prod/cen2010/briefs/c2010br-03.pdf Table DL-20: Distribution of Licensed Drivers - 2009 by Sex and Percentage in Each Age Group and Relation to Population. In: Highway Statistics 2009 [Internet]. Washington, D.C.: United States Department of Transportation, Federal Highway Administration; December 2010 [updated 3 January 2012; cited 26 January 2012]. Available from: www.fhwa.dot.gov/policyinformation/statistics/ 2009/dl20.cfm Kochanek KD, Xu J Murphy SL, Minino AM, Kung H. Deaths: Preliminary Data for 2009. National Vital Statistics Reports. 2011 Mar 16 [cited 9 January 2012]; 59(4): Table A, p3. Available from: www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_04.pdf Fatality Analysis Reporting System (FARS) Encyclopedia [Internet]. Washington, D.C.: National Highway Traffic Safety Administration; c2011 [cited 6 February 2012]. Available from: http://www-fars.nhtsa.dot.gov/QueryTool/QuerySection/Report.aspx Table VM-1: Annual Vehicle Distance Traveled in Miles and Related Data - 2009 1/ By Highway Category and Vehicle Type. In: Highway Statistics 2009. Washington, D.C.: United States Department of Transportation, Federal Highway Administration; April 2011 [updated 3 January 2012; cited 26 January 2012]. Available from: www.fhwa.dot.gov/policyinformation/statistics/2009/vm1.cfm Fleiss JL, Levin B, Paik MC. Statistical methods for rates and proportions. 3rd ed. Hoboken: John Wiley & Sons, Inc.; 2003. p28.