Northwestern Public Health Review

By Osefame Ewaleifoh

There are no miracles in medicine. We live longer, healthier lives today because of the collective efforts of people working in diverse fields from medicine to health policy and  safety engineering. These collective efforts have led to impressive “milestones” in public health. These milestones are noteworthy for several reasons. First they are remarkably simple and straightforward. Second they are often synergistic; resulting from symbiotic interactions between multiple players. Finally, these efforts that have led to progress in public health are cumulative and incremental. Understanding the actions and patterns that have driven past successes in public health can serve as an important framework and scaffold for developing new solutions to emerging public health challenges. Here I examine public health advances and inflection points that epitomize the impact of converging multi-disciplinary approaches to adressing public health challenges.

Life expectancy trends have come a long way

The average life expectancy of a child born in the US in 1900 was 50 years. By 2010, this number had increased 60% to 80 years (Fig.1). This persistent upward trend in life expectancy can be attributed to several factors including, but not limited to, improvements in medical care, safety engineering and effective public health policy. While improvements in medical care have received most of the credit for increased life expectancy, safety engineering and effective public health policy have received less recognition. In this piece, I highlight the contribution of safety engineering and health policy in promoting public health, focusing on their impact on automobile safety.

Automobile safety

From the earliest experimentation with automobiles, this mode of transportation has been heavily associated with accidents and fatalities. The earliest recorded automobile accident was in 1869 when an Irish scientist, Mary Ward, fell off and was run over by the wheels of an experimental steam car built by her cousin [1]. At the height of the Second World War in 1943, the United States lost more soldiers to automobile accidents than to combat [2]. In the last 50 years, however, automobile safety has achieved major safety milestones driven primarily by safety engineering and progressive driving legislations, grounded in public health ideation. According to the Fatality Analysis Reporting System (FARS), in 1979 there were 51,093 motor vehicle associated accidents, and by 2011 this number was reduced by 41.7% to 29,757. More significant than the absolute decrease in fatalities statistics is the downward trend. The current measures in place are leading to a consistent decrease in fatalities over time. While the current number of fatalities remains unacceptably high, the trend line is certainly encouraging (fig.2). Clearly the safety engineering and automobile health policy measures that have been implemented so far appear to be effective. So what are these measures?

Engineering measures driving automobile safety trends

The ever increasing trends in automotive safety are perhaps the best testimony to the role of safety engineering in public health. From the early introduction of hydraulic brakes to current advances in autonomous parking and brake systems as shown in the timeline above, innovations in engineering have reduced both the number of automobile accidents and the number of resulting fatalities.

Furthermore, innovations in engineering safety have gone beyond enhancing the safety features of cars, to redesigning terrains and roads. The objective of these road safety innovations has been to focus on the prevention and minimization of injury and death despite driver imperfection. According to the International Transportation Forum (ITF), the current goal is for effective safety measures to be put in place such that even “in the event of a crash, the impact energies remain below the threshold likely to produce either death or serious injury”. This strategic focus on engineering safety is an important paradigm shift in public health and raises the bar on safety engineering from simply preventing crashes to minimizing the consequences of inevitable crashes [4].

A quintessential safety engineering measure born out of this new paradigm was designating ‘speed limits’. According to the ITF, the logic for speed limits is simple; “the chances of survival for an unprotected pedestrian hit by a vehicle diminish rapidly at speeds greater than 30 km/h, whereas for a properly restrained motor vehicle occupant the critical impact speed is 50 km/h (for side impact crashes) and 70 km/h (for head-on crashes)”. Thus while we cannot entirely prevent collisions, we can reduce the fatalities associated with accidents through safety engineering measures like speed limits.

The current safety engineering focus on both preventing auto related accidents and reducing the consequence of such accidents has been directly responsible for innovations such as guard rails, detailed road warning signs, safety barriers that absorb impact and speed bumps. Advancements in road signage like zebra crossings, lane markers, gravel shoulders, and reflective mirrors with embeded small glass spheres intended to more efficiently reflect light from vehicle headlights back to the driver’s eyes, have been extremely effective in reducing automobile accidents and driving down associated fatalities.

Health Policy measures driving automobile safety trends

While safety engineering measures have been very instrumental in driving the trend of automobile safety, a powerful catalyst in this process has been strategic government policy on automobile safety anchored in public health. Although it was clear that seat belts were invaluable as a lifesaving tool after they were introduced in the 1930’s and heavily promoted in 1955 by the U.S. surgeon general [5], their true efficacy was not discovered until it became mandatory to have seat belts in all cars. This effort was championed by the New York State legislation of 1984 that made it illegal to drive in the state without wearing seatbelts [6].  Since then, this law has been adopted by 49 states in the U.S.  (NH abstaining) and many other countries around the world [6]. It is difficult to truly ascertain how many lives have been saved by seat belts, though conservative estimates by the National Highway Traffic Safety Administration (NHTSA) suggest that over 10,000 lives are saved annually by seat belts in the U.S. alone [7]. Thus, seat belts provide a concrete example of the power of legislation to leverage engineering safety in promoting public health and saving lives.

The efficacy of legislation to promote public health through safety engineering has not been limited to seat belts. Although tail lamps and brake lights were introduced in 1915 and 1919 respectively, it was not until 1986 that it became mandatory for all cars in the U.S. to have brake lights [8]. The legislation to make it illegal to drive without brake lights moved the technological innovation of automotive lighting from a nifty gadget to an essential safety-engineering tool that has saved millions of lives. The central brake light has been so successful as an engineering tool, that it is required by regulations worldwide to be centered laterally on the vehicle, through United Nations Regulation 48 [9].

Beyond promoting the application of life saving technological advancements, legislation and health policy have been important in promoting automotive safety in more direct and diverse ways. These efforts have included but have not been limited to introducing and enforcing driving age requirements, introducing and enforcing drunk driving laws and, most recently, introducing anti-texting while driving laws. While earlier legislation like anti-drinking and driving laws have been relatively more linear, the push for anti-texting while driving laws promises to be more challenging as mobile devices continue to become more deeply integrated into the fabric of our lives.

Automobile safety as a global concern

Just across the ocean however, the story of automotive safety remains rather bleak. The World Health Organization (WHO) has projected that by 2020 traffic accidents will become the third leading cause of death and disability [10]. Although only 20% of manufactured automobiles are driven in developing countries, 91% of worldwide auto accidents occur in developing countries [10]. According to the WHO, simple preventive measures can halve the rate of automobile related fatalities in most developing countries [11].

In 2010 the U.K. and the U.S. had 6.2 and 13.6 road fatalities per 100,000 motor vehicles on the road, respectively. By contrast, Liberia and Ethiopia had 73.7 and 3874.3 road fatalities per 100,000 motor vehicles, respectively [12]. Clearly, automobile safety remains a grave public health concern in both developed and developing countries, however the greatest chance to save the most lives through automotive safety now lies in developing countries.

The successful outcome of automobile safety in developed countries can provide a strategic blueprint for developing countries to follow. Given the astounding success in simple safety implementation methods and policy, there is no dire need to reinvent the wheel around the world. While the current global trend in automobile safety remains bleak, there is hope. By advocating and adopting safety legislative and engineering policies that have successfully driven automobile safety in the U.S., millions of lives around the world can potentially be saved.

The original version of this article contained erroneous road fatality rates listed in the final section, and the incorrect year for those data.  The correct rates and year are now included in the article.

References

1. Mary Ward 1827–1869, Offaly Historical & Archaeo- logical Society, Available from: http://www.offalyhistory.com/reading-resources/his tory/famous-offaly-people/mary-ward-1827-1869
2. Military death statistics, rootsweb, Ancestry.com Available from: http://www.rootsweb.ancestry. com/~pawashin/military/war-death-statistics.html
3. Fatality Analysis Reporting System (FARS) encyclo- pedia, National Highway Traffic Safety Administration (NHTSA), Available from: http://www-fars.nhtsa.dot. gov/Main/index.aspx
4. Towards Zero, Ambitious Road Safety Targets and the Safe System Approach, International Transport Forum 2008. Available from: http://www. internationaltransportforum.org/jtrc/safety/targets/ targets.html
5. Safer Cars, Popular Science, June 1955. 27-30/252
6. Seat belt laws by state, Insurance Institute for High- way Safety (IIHS), Available from: http://www.iihs.org/iihs/topics
7. NHTSA Assessment of seat belt use, National High way Traffic Safety Administration (NHTSA), Availa- ble from: http://www.nhtsa.gov/people/injury/ research/BuckleUp/ii__trends.htm
8. Kahane, C.J. and E. Hertz, NHTSA Technical Report Number DOT HS 808 696: The Long-Term Effective ness of Center High Mounted Stop Lamps in Passenger Cars and Light Trucks, 1998. Available from: http://www.nhtsa.gov/cars/ rules/regrev/evaluate/808696.html
9. World Forum for Harmonization of Vehicle Regula- tions, United Nations Economic Commission for Eu- rope, Available from: http://www.unece.org/trans/ main/wp29/wp29regs121-140.html
10. The global burden of disease, World Bank, Available from: http://www.worldbank.org/transport/roads/ saf_docs/gbd.pdf
11. UN raises child accidents alarm, BBC News. 2008. Available from: http://news.bbc.co.uk/2/hi/in_ depth/7776127.stm
12. List of countries by traffic-related death rate,
13. Wikipedia, Available from: http://en.wikipedia.org/ wiki/List_of_countries_by_traffic-related_death_rate

About the Author

Osefame Ewaleifoh is a PhD/MPH student studying herpes simplex virus neuroinvasion and transport in Greg Smith’s lab. His public health interest focuses primarily on disparities in mental health access.