Page 1 of 45

By

Dr V Laxmanan

Carnage on the

US Highways

Does Speed Kill

Forgotten Facts of

US Highway

Deaths in

1950s and 1960s

Page 2 of 45

Table of Contents

Page No Summary 3 Introduction 4 A brief review of historical fatalities data 6 Brief history of traffic safety legislation 13 The reason for the historical decrease in highway fatalities 15 Impact of NMSL on fatalities post-1973 18 Further considerations Pros and Cons 20 Conclusions 33 Table 1 Historical highway fatalities data 35 Appendix 1 42 Comments and Feedback 43

Page 3 of 45

Summary

A brief review of the historical trends in US traffic fatalities since 1929 is

presented here within the context of the recent attempts to increase the

posted speed limits on US highways most notably in Texas The public

outrage due to the ―epidemic of US highway deaths in the 1950s and the

1960s prompted Congress to hold its highly publicized hearings in 1966 and

the enactment of safey legislation signed by President Johnson later that

year However it appears that the National Maximum Speed Limit (NSML) of

55 mph enacted as an energy saving measure in 1973 following the Arab oil

embargo had a greater and immediate impact on the reduction in highway

traffic fatalities than the traffic safety legislations which no dobut had a

delayed and longer term effect (via the introdcution of vehicle safety features

like seat belts and airbags)

Some pros and cons in the debate on increasing speed limits and the impact

on fatalities and crashworthiness of vehicles have been discussed briefly A

more detailed discussion of the specific effect of speed limits (on fatalities)

may be found in a companion document where it is shown that the universal

mathematical law y = hx + c relating the number of fatal crashes (x) and the

number of fatalities (y) can be used to assess the effect of increasing or

decreasing the speed limits

A Fresh look at the Iowa Kansas Montana and Txas motor vehicle fatalities

data Effect of Speed Limits on Fatalities Texas Proofing of Vehicles

httpwwwscribdcomdoc59153773Effect-of-Speed-Limits-on-Fatalities-

Texas-Proofing-of-Vehciles

Page 2 of 45

Table of Contents

Page No Summary 3 Introduction 4 A brief review of historical fatalities data 6 Brief history of traffic safety legislation 13 The reason for the historical decrease in highway fatalities 15 Impact of NMSL on fatalities post-1973 18 Further considerations Pros and Cons 20 Conclusions 33 Table 1 Historical highway fatalities data 35 Appendix 1 42 Comments and Feedback 43

Page 3 of 45

Summary

A brief review of the historical trends in US traffic fatalities since 1929 is

presented here within the context of the recent attempts to increase the

posted speed limits on US highways most notably in Texas The public

outrage due to the ―epidemic of US highway deaths in the 1950s and the

1960s prompted Congress to hold its highly publicized hearings in 1966 and

the enactment of safey legislation signed by President Johnson later that

year However it appears that the National Maximum Speed Limit (NSML) of

55 mph enacted as an energy saving measure in 1973 following the Arab oil

embargo had a greater and immediate impact on the reduction in highway

traffic fatalities than the traffic safety legislations which no dobut had a

delayed and longer term effect (via the introdcution of vehicle safety features

like seat belts and airbags)

Some pros and cons in the debate on increasing speed limits and the impact

on fatalities and crashworthiness of vehicles have been discussed briefly A

more detailed discussion of the specific effect of speed limits (on fatalities)

may be found in a companion document where it is shown that the universal

mathematical law y = hx + c relating the number of fatal crashes (x) and the

number of fatalities (y) can be used to assess the effect of increasing or

decreasing the speed limits

A Fresh look at the Iowa Kansas Montana and Txas motor vehicle fatalities

data Effect of Speed Limits on Fatalities Texas Proofing of Vehicles

httpwwwscribdcomdoc59153773Effect-of-Speed-Limits-on-Fatalities-

Texas-Proofing-of-Vehciles

Page 3 of 45

Summary

A brief review of the historical trends in US traffic fatalities since 1929 is

presented here within the context of the recent attempts to increase the

posted speed limits on US highways most notably in Texas The public

outrage due to the ―epidemic of US highway deaths in the 1950s and the

1960s prompted Congress to hold its highly publicized hearings in 1966 and

the enactment of safey legislation signed by President Johnson later that

year However it appears that the National Maximum Speed Limit (NSML) of

55 mph enacted as an energy saving measure in 1973 following the Arab oil

embargo had a greater and immediate impact on the reduction in highway

traffic fatalities than the traffic safety legislations which no dobut had a

delayed and longer term effect (via the introdcution of vehicle safety features

like seat belts and airbags)

Some pros and cons in the debate on increasing speed limits and the impact

on fatalities and crashworthiness of vehicles have been discussed briefly A

more detailed discussion of the specific effect of speed limits (on fatalities)

may be found in a companion document where it is shown that the universal

mathematical law y = hx + c relating the number of fatal crashes (x) and the

number of fatalities (y) can be used to assess the effect of increasing or

decreasing the speed limits

A Fresh look at the Iowa Kansas Montana and Txas motor vehicle fatalities

data Effect of Speed Limits on Fatalities Texas Proofing of Vehicles

httpwwwscribdcomdoc59153773Effect-of-Speed-Limits-on-Fatalities-

Texas-Proofing-of-Vehciles

Page 4 of 45

1 Introduction

In traffic safety research we encounter two important dates or years 1966

and 1973 The main purpose here is to call attention to the historical facts

regarding the ―epidemic levels of highway traffic fatalities that engaged our

national attention in the fateful year of 1966

Does Speed Kill This is no doubt a politically charged topic with different

interest groups drawing their own conclusions and pulling in different

directions even when confronted with exactly the same facts Nonetheless

here is a humble attempt by a lone citizen to sound a cautionary note amid

the renewed attempts in many states across the US to increase the speed

limits on our highways

Page 5 of 45

The 1927 Durant Motor Star produced by William Durant the founder and the first

CEO of General Motors This car can be rented to tour San Diego for $50 to $70 per

hour plus $150 to $200 for the first half-hour httpeditorialautosmsncommost-

unusual-tourist-vehicles4

Also for the first time the Center for Disease Control (CDC) has recently

released the state-by-state societal costs of motor vehicle crashes Highway

fatalities cost $41 billion annually The CDC announcement coincides with the

kickoff of the United Nations Decade of Action an international effort aimed

at saving 5 million lives though 2020 by working cooperatively towards

greater road safety

httpwwwthecarconnectioncomnews1059966_cdc-highway-fatalities-cost-

41-billion-annually

Indeed it would be tragic if highway-accident-related fatalities were to start

increasing once again and reach the historically high level that was last seen

in 1972 the year before the Arab oil embargo of 1973 Statistical projections

of traffic fatalities show that in 2010 an estimated 32788 people died in motor

vehicle traffic crashes This is a 3 reduction over 2009 levels If these

Page 5 of 45

The 1927 Durant Motor Star produced by William Durant the founder and the first

CEO of General Motors This car can be rented to tour San Diego for $50 to $70 per

hour plus $150 to $200 for the first half-hour httpeditorialautosmsncommost-

unusual-tourist-vehicles4

Also for the first time the Center for Disease Control (CDC) has recently

released the state-by-state societal costs of motor vehicle crashes Highway

fatalities cost $41 billion annually The CDC announcement coincides with the

kickoff of the United Nations Decade of Action an international effort aimed

at saving 5 million lives though 2020 by working cooperatively towards

greater road safety

httpwwwthecarconnectioncomnews1059966_cdc-highway-fatalities-cost-

41-billion-annually

Indeed it would be tragic if highway-accident-related fatalities were to start

increasing once again and reach the historically high level that was last seen

in 1972 the year before the Arab oil embargo of 1973 Statistical projections

of traffic fatalities show that in 2010 an estimated 32788 people died in motor

vehicle traffic crashes This is a 3 reduction over 2009 levels If these

Page 6 of 45

projections are realized highway traffic fatalities will be lowest on record

(since 1949)

The graphical representation of the traffic fatality data compiled annually by

the National Highway Traffic Safety Administration (NHTSA) as seen in

Figures 1 to 4 here tells its own story Indeed here a picture is certainly

worth a thousand words Let these graphs do the talking The detailed

captions attached with each figure permit an unbiased assessment of the

traffic fatality data and will hopefully lead to a repeal of the misguided

attempts to increase speed limits This also represents a simple and new

approach to analyzing the fatality data without excessive reliance on the

calculation of simple ratios such as the widely used fatality rate

As will become obvious the national speed limit of 55 mph instituted in

the historical year of 1973 yielded the twin benefits of improved fuel

economies and reduced traffic fatalities

The 1955 Cadilla available for tours of Memphis TN

httpeditorialautosmsncommost-unusual-tourist-vehicles2

Page 7 of 45

httpwwwugptiorgpubspdfDP188pdf

httpwwwlakecountypublichealthorgindexphpbuckle-up-montana

2 A brief review of historical traffic

fatality data compiled by NHTSA

The NHTSA uses the fatality rate as its single most important measure of

traffic safety The fatality rate is the ratio yx where x is the total vehicle miles

traveled (usually expressed in billions) by all US drivers and y is the absolute

number of highway fatalities To arrive at a simple tractable number the rate

is determined per 100 million vehicle miles traveled (acronym VMT)

Although this fatality rate yx has now reached a historical low in 2010

exclusive focus on this ratio while overlooking the underlying x-y trend might

be misleading as will become evident from the graphical representation of

the historical data being attempted here

Driver Behavior

Driver Drinking

Too Fast

Not Wearing

Seat Belts

Montanarsquos Likeliest

Fatal Crash Scenario

A Pick up

A Rural road

And Seat belts not

used

Page 8 of 45

Figure 1 Graph of the absolute number of US highway fatalities since 1957 The raw

data used to prepare this graph may be found in Table 1(relegated to the end of this

document) The absolute number of highway fatalities were quite low in the 1950s

and reached a peak in the late 1960s to early 1970s and have since decreased to

levels seen in the 1950s although the vehicle miles driven (in millions) has been

increasing from 646915 in 1957 to 2560373 in the year 2000 see also Figure 2

The fatality data from other government sources have also been studied by the author

and lead to the same conclusion of a peak in highway deaths around the late 1960s to

early 1970s

Page 9 of 45

Figure 2a Graphical representation of the absolute number of US highway fatalities

versus annual vehicle miles driven (in trillions) The number of miles driven by US

drivers has increased each year since 1957 as seen in Table 1 The absolute number

of highway fatalities has increased as well reaching a peak in the late 1960s to early

1970s The same peak is also seen here in the graph of the absolute number of

highway fatalities versus vehicle miles driven Improvements in vehicle safety devices

(notably seat belts and airbags) coupled with the institution of the national highway

speed limits (starting mid 1970s) and also improved highways are the primary

reasons for the decrease in fatalities These historical trends suggest that renewed

attempts to increase the speed limits on our highways would be counterproductive

and may eventually lead once again to an increase in fatalities with tragic

Page 10 of 45

consequences

Figure 2b Graphical representation of the US highway fatality data for the period

1921-1982 The first year for which a fatality rate yx could be computed is 1921 The

number of fatalities was 13253 and VMT was 5503 billion yielding a fatality rate of

2408 per 100 million VMT The fatality rate for any year is the slope of the ray ie

the straight line joining the (x y) data point back to the origin (00) of this graph see

dashed line for 1921 superimposed on to the graph The fatality rates (slopes of such

rays) had been declining quite consistently although the absolute number of fatalities

increased as seen here ultimately leading to the Congressional hearing in 1966 Is

VMT the single most important reason for the increasing fatalities

Page 11 of 45

Figure 3 Graphical representation of the traffic fatality data for the 15 year period

1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on

the magnified scale used here) and hence the fatality rate has been observed over

the three-year period 2007-2009 However it should be noted that the x-y scatter

graph here shows a general upward trend with fatalities actually increasing with

increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period

spanning 1994-2006 although the rate yx shows a misleading downward trend Why

is the rate yx going down

The reason is very simple and it may be just a mathematical artifact The equation of

the best-fit straight line through the most recent data points is of the form y = hx + c

= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x

here is VMT in billions The numerical value determined using this equation must be

divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the

ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing

values of x because of the nonzero intercept c Unlike the ray through the origin the

best-fit line does not pass through the origin (00) If we consider only the most

Page 12 of 45

recent data the intercept c is positive and fatality rates yx decrease with increasing

VMT and increasing fatalities In the earlier era both the slope h and intercept c had

very different values due to several factors being discussed here (speed limits

technology highway design etc)

Table 2 Traffic fatality data for the recent 15-year period

1994-2009 (Source NHTSA)

Year

Highway

fatalities y

Vehicle miles

traveled

VMT

(billions) x

Fatality rate

yx per 100

million VMT

Fatal crashes

1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797

Page 13 of 45

Figure 4 The most significant metric used by NHTSA is the fatality rate per 100

million vehicles miles traveled (VMT) This is now at a historical low of 113 for

2009 having declined year after year from 173 in 1994 The NHTSA however also

compiles other types of data on crashes There are three types of crashes fatal

injury but no death and property damage only A careful review of this crash data

for the period 1994-2009 reveals the obvious the lower the number of (fatal)

crashes x the lower the number of highway-accident-related fatalities y It is also

obvious that the number of fatalities per crash is greater than one ie more than one

person is being killed when one of more vehicles experience a crash

Clearly this is the single most important piece of information that one needs to

reduce the number of fatalities on our highways Vehicle design and engineering as

well as all other policy matters (legal political social environmental financial)

must be guided by this simple graph The best-fit line through the data derived using

simple linear regression has the equation y = hx + c = 114x ndash 10266 and is

Page 14 of 45

superimposed on to the data The design engineering goal and societal goal should

be to reduce the slope h of this statistically significant best-fit line to its ideal value of

h = 1 A fatal crash by definition is one where at least one person dies either an

occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1

Photograph of an accident scene from the period 1955-1965

httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml

3 A Brief History of Traffic Safety Legislation

The following is extracted from the Wikipedia article on National Highway

Traffic Safety Administration (NHTSA)

httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration

In 1965 and 1966 public pressure grew in the US to increase the safety of

cars The number of deaths on US highways were increasing year after year

Page 9 of 45

Figure 2a Graphical representation of the absolute number of US highway fatalities

versus annual vehicle miles driven (in trillions) The number of miles driven by US

drivers has increased each year since 1957 as seen in Table 1 The absolute number

of highway fatalities has increased as well reaching a peak in the late 1960s to early

1970s The same peak is also seen here in the graph of the absolute number of

highway fatalities versus vehicle miles driven Improvements in vehicle safety devices

(notably seat belts and airbags) coupled with the institution of the national highway

speed limits (starting mid 1970s) and also improved highways are the primary

reasons for the decrease in fatalities These historical trends suggest that renewed

attempts to increase the speed limits on our highways would be counterproductive

and may eventually lead once again to an increase in fatalities with tragic

Page 10 of 45

consequences

Figure 2b Graphical representation of the US highway fatality data for the period

1921-1982 The first year for which a fatality rate yx could be computed is 1921 The

number of fatalities was 13253 and VMT was 5503 billion yielding a fatality rate of

2408 per 100 million VMT The fatality rate for any year is the slope of the ray ie

the straight line joining the (x y) data point back to the origin (00) of this graph see

dashed line for 1921 superimposed on to the graph The fatality rates (slopes of such

rays) had been declining quite consistently although the absolute number of fatalities

increased as seen here ultimately leading to the Congressional hearing in 1966 Is

VMT the single most important reason for the increasing fatalities

Page 11 of 45

Figure 3 Graphical representation of the traffic fatality data for the 15 year period

1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on

the magnified scale used here) and hence the fatality rate has been observed over

the three-year period 2007-2009 However it should be noted that the x-y scatter

graph here shows a general upward trend with fatalities actually increasing with

increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period

spanning 1994-2006 although the rate yx shows a misleading downward trend Why

is the rate yx going down

The reason is very simple and it may be just a mathematical artifact The equation of

the best-fit straight line through the most recent data points is of the form y = hx + c

= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x

here is VMT in billions The numerical value determined using this equation must be

divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the

ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing

values of x because of the nonzero intercept c Unlike the ray through the origin the

best-fit line does not pass through the origin (00) If we consider only the most

Page 12 of 45

recent data the intercept c is positive and fatality rates yx decrease with increasing

VMT and increasing fatalities In the earlier era both the slope h and intercept c had

very different values due to several factors being discussed here (speed limits

technology highway design etc)

Table 2 Traffic fatality data for the recent 15-year period

1994-2009 (Source NHTSA)

Year

Highway

fatalities y

Vehicle miles

traveled

VMT

(billions) x

Fatality rate

yx per 100

million VMT

Fatal crashes

1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797

Page 13 of 45

Figure 4 The most significant metric used by NHTSA is the fatality rate per 100

million vehicles miles traveled (VMT) This is now at a historical low of 113 for

2009 having declined year after year from 173 in 1994 The NHTSA however also

compiles other types of data on crashes There are three types of crashes fatal

injury but no death and property damage only A careful review of this crash data

for the period 1994-2009 reveals the obvious the lower the number of (fatal)

crashes x the lower the number of highway-accident-related fatalities y It is also

obvious that the number of fatalities per crash is greater than one ie more than one

person is being killed when one of more vehicles experience a crash

Clearly this is the single most important piece of information that one needs to

reduce the number of fatalities on our highways Vehicle design and engineering as

well as all other policy matters (legal political social environmental financial)

must be guided by this simple graph The best-fit line through the data derived using

simple linear regression has the equation y = hx + c = 114x ndash 10266 and is

Page 14 of 45

superimposed on to the data The design engineering goal and societal goal should

be to reduce the slope h of this statistically significant best-fit line to its ideal value of

h = 1 A fatal crash by definition is one where at least one person dies either an

occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1

Photograph of an accident scene from the period 1955-1965

httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml

3 A Brief History of Traffic Safety Legislation

The following is extracted from the Wikipedia article on National Highway

Traffic Safety Administration (NHTSA)

httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration

In 1965 and 1966 public pressure grew in the US to increase the safety of

cars The number of deaths on US highways were increasing year after year

Page 10 of 45

consequences

Figure 2b Graphical representation of the US highway fatality data for the period

1921-1982 The first year for which a fatality rate yx could be computed is 1921 The

number of fatalities was 13253 and VMT was 5503 billion yielding a fatality rate of

2408 per 100 million VMT The fatality rate for any year is the slope of the ray ie

the straight line joining the (x y) data point back to the origin (00) of this graph see

dashed line for 1921 superimposed on to the graph The fatality rates (slopes of such

rays) had been declining quite consistently although the absolute number of fatalities

increased as seen here ultimately leading to the Congressional hearing in 1966 Is

VMT the single most important reason for the increasing fatalities

Page 11 of 45

Figure 3 Graphical representation of the traffic fatality data for the 15 year period

1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on

the magnified scale used here) and hence the fatality rate has been observed over

the three-year period 2007-2009 However it should be noted that the x-y scatter

graph here shows a general upward trend with fatalities actually increasing with

increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period

spanning 1994-2006 although the rate yx shows a misleading downward trend Why

is the rate yx going down

The reason is very simple and it may be just a mathematical artifact The equation of

the best-fit straight line through the most recent data points is of the form y = hx + c

= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x

here is VMT in billions The numerical value determined using this equation must be

divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the

ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing

values of x because of the nonzero intercept c Unlike the ray through the origin the

best-fit line does not pass through the origin (00) If we consider only the most

Page 12 of 45

recent data the intercept c is positive and fatality rates yx decrease with increasing

VMT and increasing fatalities In the earlier era both the slope h and intercept c had

very different values due to several factors being discussed here (speed limits

technology highway design etc)

Table 2 Traffic fatality data for the recent 15-year period

1994-2009 (Source NHTSA)

Year

Highway

fatalities y

Vehicle miles

traveled

VMT

(billions) x

Fatality rate

yx per 100

million VMT

Fatal crashes

1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797

Page 13 of 45

Figure 4 The most significant metric used by NHTSA is the fatality rate per 100

million vehicles miles traveled (VMT) This is now at a historical low of 113 for

2009 having declined year after year from 173 in 1994 The NHTSA however also

compiles other types of data on crashes There are three types of crashes fatal

injury but no death and property damage only A careful review of this crash data

for the period 1994-2009 reveals the obvious the lower the number of (fatal)

crashes x the lower the number of highway-accident-related fatalities y It is also

obvious that the number of fatalities per crash is greater than one ie more than one

person is being killed when one of more vehicles experience a crash

Clearly this is the single most important piece of information that one needs to

reduce the number of fatalities on our highways Vehicle design and engineering as

well as all other policy matters (legal political social environmental financial)

must be guided by this simple graph The best-fit line through the data derived using

simple linear regression has the equation y = hx + c = 114x ndash 10266 and is

Page 14 of 45

superimposed on to the data The design engineering goal and societal goal should

be to reduce the slope h of this statistically significant best-fit line to its ideal value of

h = 1 A fatal crash by definition is one where at least one person dies either an

occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1

Photograph of an accident scene from the period 1955-1965

httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml

3 A Brief History of Traffic Safety Legislation

The following is extracted from the Wikipedia article on National Highway

Traffic Safety Administration (NHTSA)

httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration

In 1965 and 1966 public pressure grew in the US to increase the safety of

cars The number of deaths on US highways were increasing year after year

Page 11 of 45

Figure 3 Graphical representation of the traffic fatality data for the 15 year period

1994-2009 A sudden precipitous drop in the absolute number of fatalities (at least on

the magnified scale used here) and hence the fatality rate has been observed over

the three-year period 2007-2009 However it should be noted that the x-y scatter

graph here shows a general upward trend with fatalities actually increasing with

increasing VMT (as in the earlier era 1950s and 1960s) during the 12-year period

spanning 1994-2006 although the rate yx shows a misleading downward trend Why

is the rate yx going down

The reason is very simple and it may be just a mathematical artifact The equation of

the best-fit straight line through the most recent data points is of the form y = hx + c

= 2865 x + 34420 where h is the slope of the line and c the intercept (Note that x

here is VMT in billions The numerical value determined using this equation must be

divided by 10 to get the rate per 100 M VMT) Hence the fatality rate given by the

ratio yx = h + (cx) = 2865 + 34420x can actually decrease with increasing

values of x because of the nonzero intercept c Unlike the ray through the origin the

best-fit line does not pass through the origin (00) If we consider only the most

Page 12 of 45

recent data the intercept c is positive and fatality rates yx decrease with increasing

VMT and increasing fatalities In the earlier era both the slope h and intercept c had

very different values due to several factors being discussed here (speed limits

technology highway design etc)

Table 2 Traffic fatality data for the recent 15-year period

1994-2009 (Source NHTSA)

Year

Highway

fatalities y

Vehicle miles

traveled

VMT

(billions) x

Fatality rate

yx per 100

million VMT

Fatal crashes

1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797

Page 13 of 45

Figure 4 The most significant metric used by NHTSA is the fatality rate per 100

million vehicles miles traveled (VMT) This is now at a historical low of 113 for

2009 having declined year after year from 173 in 1994 The NHTSA however also

compiles other types of data on crashes There are three types of crashes fatal

injury but no death and property damage only A careful review of this crash data

for the period 1994-2009 reveals the obvious the lower the number of (fatal)

crashes x the lower the number of highway-accident-related fatalities y It is also

obvious that the number of fatalities per crash is greater than one ie more than one

person is being killed when one of more vehicles experience a crash

Clearly this is the single most important piece of information that one needs to

reduce the number of fatalities on our highways Vehicle design and engineering as

well as all other policy matters (legal political social environmental financial)

must be guided by this simple graph The best-fit line through the data derived using

simple linear regression has the equation y = hx + c = 114x ndash 10266 and is

Page 14 of 45

superimposed on to the data The design engineering goal and societal goal should

be to reduce the slope h of this statistically significant best-fit line to its ideal value of

h = 1 A fatal crash by definition is one where at least one person dies either an

occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1

Photograph of an accident scene from the period 1955-1965

httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml

3 A Brief History of Traffic Safety Legislation

The following is extracted from the Wikipedia article on National Highway

Traffic Safety Administration (NHTSA)

httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration

In 1965 and 1966 public pressure grew in the US to increase the safety of

cars The number of deaths on US highways were increasing year after year

Page 12 of 45

recent data the intercept c is positive and fatality rates yx decrease with increasing

VMT and increasing fatalities In the earlier era both the slope h and intercept c had

very different values due to several factors being discussed here (speed limits

technology highway design etc)

Table 2 Traffic fatality data for the recent 15-year period

1994-2009 (Source NHTSA)

Year

Highway

fatalities y

Vehicle miles

traveled

VMT

(billions) x

Fatality rate

yx per 100

million VMT

Fatal crashes

1994 40716 2358 173 36254 1995 41817 2423 173 37241 1996 42065 2486 169 37494 1997 42013 2562 164 37324 1998 41501 2632 158 37107 1999 41717 2691 155 37140 2000 41945 2747 153 37526 2001 42196 2797 151 37862 2002 43005 2856 151 38491 2003 42884 2890 148 38477 2004 42836 2965 144 38444 2005 43510 2989 146 39252 2006 42708 3014 1 42 38648 2007 41259 3032 136 37435 2008 37423 2974 126 34172 2009 33808 2979 113 30797

Page 13 of 45

Figure 4 The most significant metric used by NHTSA is the fatality rate per 100

million vehicles miles traveled (VMT) This is now at a historical low of 113 for

2009 having declined year after year from 173 in 1994 The NHTSA however also

compiles other types of data on crashes There are three types of crashes fatal

injury but no death and property damage only A careful review of this crash data

for the period 1994-2009 reveals the obvious the lower the number of (fatal)

crashes x the lower the number of highway-accident-related fatalities y It is also

obvious that the number of fatalities per crash is greater than one ie more than one

person is being killed when one of more vehicles experience a crash

Clearly this is the single most important piece of information that one needs to

reduce the number of fatalities on our highways Vehicle design and engineering as

well as all other policy matters (legal political social environmental financial)

must be guided by this simple graph The best-fit line through the data derived using

simple linear regression has the equation y = hx + c = 114x ndash 10266 and is

Page 14 of 45

superimposed on to the data The design engineering goal and societal goal should

be to reduce the slope h of this statistically significant best-fit line to its ideal value of

h = 1 A fatal crash by definition is one where at least one person dies either an

occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1

Photograph of an accident scene from the period 1955-1965

httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml

3 A Brief History of Traffic Safety Legislation

The following is extracted from the Wikipedia article on National Highway

Traffic Safety Administration (NHTSA)

httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration

In 1965 and 1966 public pressure grew in the US to increase the safety of

cars The number of deaths on US highways were increasing year after year

Page 13 of 45

Figure 4 The most significant metric used by NHTSA is the fatality rate per 100

million vehicles miles traveled (VMT) This is now at a historical low of 113 for

2009 having declined year after year from 173 in 1994 The NHTSA however also

compiles other types of data on crashes There are three types of crashes fatal

injury but no death and property damage only A careful review of this crash data

for the period 1994-2009 reveals the obvious the lower the number of (fatal)

crashes x the lower the number of highway-accident-related fatalities y It is also

obvious that the number of fatalities per crash is greater than one ie more than one

person is being killed when one of more vehicles experience a crash

Clearly this is the single most important piece of information that one needs to

reduce the number of fatalities on our highways Vehicle design and engineering as

well as all other policy matters (legal political social environmental financial)

must be guided by this simple graph The best-fit line through the data derived using

simple linear regression has the equation y = hx + c = 114x ndash 10266 and is

Page 14 of 45

superimposed on to the data The design engineering goal and societal goal should

be to reduce the slope h of this statistically significant best-fit line to its ideal value of

h = 1 A fatal crash by definition is one where at least one person dies either an

occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1

Photograph of an accident scene from the period 1955-1965

httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml

3 A Brief History of Traffic Safety Legislation

The following is extracted from the Wikipedia article on National Highway

Traffic Safety Administration (NHTSA)

httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration

In 1965 and 1966 public pressure grew in the US to increase the safety of

cars The number of deaths on US highways were increasing year after year

Page 14 of 45

superimposed on to the data The design engineering goal and societal goal should

be to reduce the slope h of this statistically significant best-fit line to its ideal value of

h = 1 A fatal crash by definition is one where at least one person dies either an

occupant or a non-motorist in the path of the vehicle Hence the ideal slope h = 1

Photograph of an accident scene from the period 1955-1965

httpwwwcorinthsocialhistoryprojectorghtmlhighwaytollshtml

3 A Brief History of Traffic Safety Legislation

The following is extracted from the Wikipedia article on National Highway

Traffic Safety Administration (NHTSA)

httpenwikipediaorgwikiNational_Highway_Traffic_Safety_Administration

In 1965 and 1966 public pressure grew in the US to increase the safety of

cars The number of deaths on US highways were increasing year after year

Page 15 of 45

see Figure 1 and in 1966 Congress held a series of highly publicized

hearings on highway safety This led to the legislation for mandatory

installation of seat belts which also created the US Department of

Transportation (on Oct 15 1966)

httpwwwemsgovpdf2011EMSWeek2011_Stricklandpdf

The following is extracted from a Washington Post article on

NHTSA dated April 2 2002

httpwwwwashingtonpostcomwp-srvbusinessincludesnhtsa_primerhtm

In 1966 after decades of rising traffic fatalities (also vividly illustrated in

Figures 1 and 2 here) the publication of Ralph Naders Unsafe at Any

Speed and increasing public outcry for safer automobiles Congress held a

series of highly publicized hearings on creating a regulatory agency for traffic

safety Among the witnesses was William Haddon an epidemiologist who

introduced the idea that traffic accidents could be analyzed scientifically and

injuries reduced by changing auto design such as installing collapsible

steering columns safety glass head rests and seat belts

Congress passed the Highway Safety Act of 1966 creating the National

Highway Safety Bureau with Haddon as its first administrator The bureau

became NHTSA in 1970 under the newly established Department of

Transportation An early Nader convert Joan Claybrook headed NHTSA

under President Carter and now runs Naders organization Public Citizen

National Traffic and Motor Vehicle Safety Act

httpwwwanswerscomtopicnational-traffic-and-motor-vehicle-safety-act

Signed into law by President Lyndon Johnson on September 9 1966 this act

created the first mandatory federal safety standards for motor vehicles The

act was motivated by a variety of factors First and foremost the public was

growing increasingly concerned over the rising number of traffic fatalities on

the nations roads Such fatalities had increased by nearly 30 percent

between 1960 and 1965 and experts forecasted 100000 such deaths

Page 16 of 45

annually by 1975 unless something was done to improve traffic safety

Adding fuel to the fire Ralph Naders Unsafe at Any Speed published in

November 1965 criticized the automobile industry for neglecting safety in

favor of power and styling when designing new vehicles

4 The reason for the historical

decrease in highway fatalities

A recent news item see link given below regarding renewed attempts to

increase the speed limit by many states prompted this write up by the

present author who has studied traffic fatality data extensively and analyzed

them very carefully over the last several years

httpmoneymsncomauto-insurancewhy-speed-limits-are-

risingaspxGT1=33033

Residents of Metro Detroit area who frequently cross into Ohio from

Michigan notice that the speed limit has now increased in Ohio The speed

limit on Michigan highways was increased to 70 mph in the late 1990s but

Ohio retained its lower speed limit for many years leading Michigan drivers to

experience a ―speed trap of sorts The speed limit is also increasing in many

other states notably Texas where it is proposed to increase it to 85 mph at

least in West Texas

Historically speaking from a traffic fatality standpoint we must consider two

important dates 1966 and 1973 Only 1973 the year of the Arab oil embargo

following the Arab-Israeli war (that led to what President Obama has recently

called the pre-1967 border for Middle East peace) is mentioned in the above

article It fails to mention the significance of the year 1966

Prior to 1966 there was actually NO speed limit in many Western states and

deaths due to highway accidents were increasing year after year The

Page 17 of 45

number of highway fatalities went up from 38702 in 1957 to 51524 in 1965

a 33 increase over the 1957 level and an additional 12822 deaths in 1965

compared to 1957 It was this carnage on the US highways that forced

Congress to hold its hearings on highway traffic fatalities in 1966

Nonetheless a careful examination of the fatality data in Table 1 shows that

notwithstanding the highly publicized Congressional hearings of 1966 and

new safety legislation that was enacted the absolute number of fatalities

continued to increase after 1966 and only started decreasing after 1973

Vehicle designs especially the introduction of safety features (even the

simplest like safety belts) did not change significantly between 1966 and

1973 Nonetheless post-1973 we begin to see a dramatic turnaround

Why

After the 1973 Arab oil embargo a nationwide maximum speed limit (NMSL)

of 55 mph was imposed and accepted in the USA (effective Jan 1 1974)

during the Nixon administration primarily as an effort to conserve fuel and

reduce the US vulnerability to oil imports The unintended and indeed

fortunate consequence of this reduced speed limit was the immediate

reduction in the fatalities revealed in Figures 2 and 3 This is the real reason

for the peaks in highway fatalities observed in these two graphs

The Congressional hearings of 1966 did eventually have an impact but it was

a delayed one The impact of the 1973 nationwide speed limit of 55 mph was

however immediate as we see from the magnified plot of the same data in

Figure 5 and a closer examination of the raw fatality data in Table 1

The number of highway-accident-related fatalities decreased immediately

from a high of 55704 in 1972 to just 46078 in 1974 a 173 drop see

arrows There were 9626 fewer deaths annually even with a slight increase

in the vehicle miles driven (see Table 1) Indeed the number of highway

death reached its absolute peak value in 1972 never to be seen again

Fatalities have been decreasing every since with slight fluctuations about

each new low value

Page 18 of 45

Figure 5 Expanded view of the fatality data showing the immediate impact of the

national speed limit of 55 mph following the Arab oil embargo of 1973 Note that

fatalities continued to rise between 1966 and 1973 in spite of the highly publicized

Congressional hearings in 1966 and the traffic safety legislation enacted soon after

Each new low is probably associated with vehicle safety innovations and the

improvements in vehicle design and engineering The combined beneficial

effect of improved vehicle designs primarily the introduction of seat belts

and the laws enforcing usage of seat belts aided by the reduced speed

limits contributed to the continued decline in the absolute number of fatalities

that started since 1973 and has continued to this day The subsequent

introduction of other safety features notably air bags has contributed to a

further reduction in highway fatalities

Page 19 of 45

State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell

Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at

an intersection when a truck (seen behind the wrecked car) entered this accident

prone intersection (part of a highway safety corridor where signs are posted to

reduce unsafe driver behavior) There have been four accidents at this intersection

since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-

injured-in-route-30-wreck-2011053104165420story

5 Numerical calculations of decline in

fatalities and the impact of NMSL post-1973

Letlsquos consider the decline in fatalities between 1972 the last year before the

adoption of the NMSL and 1974 the first year following its adoption after the

Arab oil embargo There was an immediate decrease in the number of

fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x

= 20758 millions The NHTSA data used here may be found in the table at

the end of this document The numerical value of the rate of change per

billion VMT (ie neglecting the sign) was therefore

yx = 4525 fatalitiesbillion VMT (1972-1974)

Page 18 of 45

Figure 5 Expanded view of the fatality data showing the immediate impact of the

national speed limit of 55 mph following the Arab oil embargo of 1973 Note that

fatalities continued to rise between 1966 and 1973 in spite of the highly publicized

Congressional hearings in 1966 and the traffic safety legislation enacted soon after

Each new low is probably associated with vehicle safety innovations and the

improvements in vehicle design and engineering The combined beneficial

effect of improved vehicle designs primarily the introduction of seat belts

and the laws enforcing usage of seat belts aided by the reduced speed

limits contributed to the continued decline in the absolute number of fatalities

that started since 1973 and has continued to this day The subsequent

introduction of other safety features notably air bags has contributed to a

further reduction in highway fatalities

Page 19 of 45

State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell

Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at

an intersection when a truck (seen behind the wrecked car) entered this accident

prone intersection (part of a highway safety corridor where signs are posted to

reduce unsafe driver behavior) There have been four accidents at this intersection

since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-

injured-in-route-30-wreck-2011053104165420story

5 Numerical calculations of decline in

fatalities and the impact of NMSL post-1973

Letlsquos consider the decline in fatalities between 1972 the last year before the

adoption of the NMSL and 1974 the first year following its adoption after the

Arab oil embargo There was an immediate decrease in the number of

fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x

= 20758 millions The NHTSA data used here may be found in the table at

the end of this document The numerical value of the rate of change per

billion VMT (ie neglecting the sign) was therefore

yx = 4525 fatalitiesbillion VMT (1972-1974)

Page 19 of 45

State police Trooper First Class Jeffrey Flowers looking at a car in which a Boswell

Pennsylvania woman was injured Tuesday (May 31 2011) The accident occurred at

an intersection when a truck (seen behind the wrecked car) entered this accident

prone intersection (part of a highway safety corridor where signs are posted to

reduce unsafe driver behavior) There have been four accidents at this intersection

since 2006 none fatal httpwwwdailyamericancomnewssomersetda-ot-woman-

injured-in-route-30-wreck-2011053104165420story

5 Numerical calculations of decline in

fatalities and the impact of NMSL post-1973

Letlsquos consider the decline in fatalities between 1972 the last year before the

adoption of the NMSL and 1974 the first year following its adoption after the

Arab oil embargo There was an immediate decrease in the number of

fatalities by 9393 ie y = -9393 with a slight increase in the VMT ie x

= 20758 millions The NHTSA data used here may be found in the table at

the end of this document The numerical value of the rate of change per

billion VMT (ie neglecting the sign) was therefore

yx = 4525 fatalitiesbillion VMT (1972-1974)

Page 20 of 45

It is instructive to compare this rate of change in fatalities with similar short

periods of a decline in fatalities in the pre-1973 era when speed limits were

much higher The absolute number of fatalities declined over a relatively

short period with both an increase and a decrease in VMT The results are

given below and are self-explanatory

yx = 454 fatalitiesbillion VMT (1953-54) decline with increase in VMT

yx = 655 fatalitiesbillion VMT (1942-43) decline with decrease in VMT

yx = 1739 fatalitiesbillion VMT (1941-42) decline with decrease in VMT

yx = 4528 fatalitiesbillion VMT (1937-39) decline with increase in VMT

yx = 2548 fatalitiesbillion VMT (1931-32) decline with decrease in VMT

The rate of decline observed between 1953 and 1954 with an increase in

VMT was just one-tenth of that observed following the adoption of the 55

mph speed limit The war years (1941-43 WWII) and the Great Depression

era (1931-32) were accompanied by big declines in fatalities with decreasing

VMT but the rate of change was still significantly lower than observed after

the adoption of the NMSL

The only apparently inexplicable decline is that between 1937 and 1939

where a nearly identical high rate of decline was observed Notice also the

big drop in the traditional fatality rate between 1937 and 1938 This large drop

appears to coincide with the creation of the National Safety Council (NSC) by

William H Cameron in June 1937 (see link below) with its far-flung campaign

of education legislation research highway engineering and traffic training

undertaken by the NSC and some two dozen other groups with the backing of the

automotive industry through its Automotive Safety Foundation Other factors

unknown to the present author probably also played a role

httpwwwtimecomtimemagazinearticle0917188379700htmlixzz1O2G

7rnUg

Page 21 of 45

These simple computations here however reveal the significant effect of

reduced speed limits on highway fatalities much more so than other factors

6 Further Considerations Pros and Cons

The singular effect of increased speeds (or speeding) on highway fatalities

has been studied and demonstrated by a number of industry sources such

as the Insurance Institute for Highway Safety (IIHS) Consumers Union and

also by government researchers

httpwwwsmartmotoristcomtraffic-and-safety-guidelineexcessive-speed-is-

a-factor-in-one-third-of-all-fatal-crasheshtml

httpwwwconsumersunionorgotherspeedlimitsspeed031500a2htm

Speed ndash defined as exceeding the posted speed limit or driving too fast for

given conditions ndash is a factor in nearly one-third of all fatal crashes Besides

fatality in 1998 nearly 40000 people were critically injured in speed-related

crashes and nearly 72000 were moderately injured

The salutary and immediate beneficial effect of the nationwide 55 mph speed

limit has been noted by other researchers (see Susan Ferguson link below)

httpwwwnhtsagovpeopleinjuryenforcespeed_forum_presentationsfergu

sonpdf

After a partial repeal of this law in 1987 which granted states the authority to

increase speed limit (especially in rural interstates) a 1989 study showed a

15 increase in fatalities in rural interstates and a 5 increase in non-rural

interstates Unfortunately such studies often tend to be discounted by

advocates of increasing the speed limits as being produced by biased

industry sources

Similar conclusions were also presented by NHTSA in February 1998 in its

report to the Congress entitled ―Report to Congress The Effect of Increased

Speed Limits in the Post-NMSL Era see link given below Among its key

Page 22 of 45

findings is the following quoted in its entirety NMSL refers to the National

Maximum Speed Limit legislated after the Arab oil embargo of 1973

httpwww-nrdnhtsadotgovPubs808-637PDF

hellip Nevertheless it is important to note that data currently available from the

National Highway Traffic Safety Administrationrsquos (NHTSA) Fatality Analysis

Reporting System (FARS) shows that states that increased speed limits in 1996

experienced approximately 350 more Interstate fatalities than would have been

expected based on historical trends -- about 9 percent above expectations

Concurrently the Interstate fatalities experienced in states that did not increase speed

limits in 1996 was consistent with pre-1996 trends The estimated increase in

Interstate fatalities found in this study while smaller in magnitude compared to the

estimated change in fatalities found in 1987 following the increase of speed limits on

rural Interstates does follow the historical pattern of increases in fatalities being

associated with increases in posted speed limits

The annual crash reports compiled by NHTSA see Table 3 indicate that the

number of fatal crashes (and hence fatalities using the regression equation

developed in Figure 4) increase as the posted speed limits increase

Page 23 of 45

Table 3 Posted speed limits and number of crashes

Speed Limit Crashes (2008) Crashes (2009)

30 mph or less 3705 3277 35 or 40 mph 6115 5516 45 or 50 mph 6461 6074

55 mph 9794 8847 60 mph or higher 6908 6124

Total 34017 30797

Source httpwww-nrdnhtsadotgovPubs811402EEpdf

61 Studies cited in favor of lower speed limits

A detailed analysis of speeding related fatalities (see link below) by NHTSA

shows that a third of all crashes involve speeding ie at least one driver was

speeding

httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R

elated20Fatal20Motor20Vehicle20Traffic20Crashespdf

Furthermore the above report which covers the period 1983-2002

indicates that immediately after the NMSL was completely abolished in

December 1995 the number of speeding related fatalities at speeds

above 65 mph increased from just 15 in 1995 to a 677 in 1996 (see Table

62 on page 43 of above report) It continued to increase in the years

since climbing to 930 in 2000

More detailed studies similar to that noted above by researchers at the

University of Illinois Chicago led by Lee S Friedman again lead to the

conclusion that higher speed limits lead to an increase in the number of

fatalities (see American Journal of Public Health online July 16 2009)

httphealthusnewscomhealth-newsmanaging-your-

healthcarearticles20090716deaths-injuries-increase-with-higher-speed-

limits

Page 24 of 45

httpwwwmedpagetodaycomPublicHealthPolicyPublicHealth15122

httpwwwamericaneercomspeed-limits

httpwwwactuarialoutpostcomactuarial_discussion_forumarchiveindexph

pt-171870html

For the study period 1995-2005 these researchers found that 12545 deaths

and 36582 injuries could be attributed to the increased speed limits The

benefits of reduced speed limits are stated quite eloquently by Dr Friedman

and are reproduced below (from above news article see link)

Reduced speed limits would save lives Friedman said They would also reduce

gas consumption cut emissions of air pollutants save valuable years of productivity

(lost due to injuries)and reduce the societal cost of motor vehicle crashes (due to

both fatal crashes and due to nonfatal and severe life-changing injuries) he added

Friedman and coworkers have also shown that increasing the speed limit led

to an immediate increase in the number of fatalities on Israeli roadways (see

link below)

httpinjurypreventionbmjcomcontent133156

The effect of speeding is very significant especially in rural areas resulting

in significantly higher fatalities Fatality rates are frequently double or triple

that in urban areas (see link below)

httpsafetyfhwadotgovspeedmgtdata_factsdocsspeeding_ruralpdf

As of Jan 1 2005 five Midwestern states had increased the speed limits to

above 65 mph (Illinois Iowa Kansas Minnesota Missouri Nebraska and

South Dakota) whereas three (Illinois Iowa and Wisconsin) had not All the

five states with increased speed limits showed a 7 to 13 increase in

fatalities The NHTSA study considered an eight year period before and after

the change in Dec 1995 (see Table 1 in link below) The collective experience

of the states that did NOT increase the speed limit was a 7 decline in

fatalities (see Table 2 of link below)

httpwwwiowadotgovmvdodsstats2006speedstudypdf

Page 25 of 45

Moreover Table 5 in the above study shows the effect of imposing the NMSL

of 55 mph in Iowa and its repeal in 1995 Considering a four-year average

before 1974 when the speed limit was 75 mph there were 35 fatal crashes

with 43 fatalities In the first four years after the 55 mph there were only 23

fatal crashes and 28 fatalities In the last four years before the repeal of 55

mph in 1995 there was a further decline to 14 fatal crashes with 17 fatalities

The Iowa fatality data will be discussed in more detail separately (in a later report)

since it provides the opportunity to assess the effect of a change in the speed limit

on the relationship between number of fatalities and fatal crashes (as seen in

Figure 4 for the US as a whole)

North of the US border Canadians seem to be citing the ―shocking increase

in highway fatalities in the US states where the speed limits were raised to

curb their own speed limits

httparchivesafety-councilorginfotrafficspeed-02html

httparchivesafety-councilorginfotrafficspeedhtml

Speed kills but speed also sells notes the second of the above news items

Manufacturers are producing more high performance cars (with higher horse

power to weight ratio) and ads feature enticing cars that race and swerve in

miraculous ways on empty roads These subliminal messages encourage

drivers especially young drivers to break the speed limit leading to the

absolute increase in highway fatalities (although the rate itself is going

down) The article emphasizes the need to enforce the speed limit on

Canadian highways and in cities where street racing is becoming a problem

62 Studies cited by opponents of lower speed limits

In fairness to quote the opponents on the other side of this debate Montana

reverted back to Reasonable and Prudent speed limits when the National

Maximum Speed Limit was repealed in 1995 and appears to have

experienced no significant increase in fatalities

Page 26 of 45

httpwwwhwysafetycomhwy_montanahtm

httpwwwmotoristsorgpressmontana-no-speed-limit-safety-paradox

httpwwwsouthbayriderscomforumsshowthreadphpt=81453amppage=1

Likewise studies in the state of Maryland showed no significant increase in

highway fatalities when the speed limit was increased from 55 mph to 75

mph The reason might simply be that drivers were already speeding much

more so when the speed limit was 55 mph than after the increase to 75 mph

In other words the fatalities data already reflects the effect of higher speeds

(not speed limits) on the number of fatalities

In Utah the experimental increase in the speed limit to 80 mph was

considered to be a success in terms of safety

httpautosaolcomarticleutah-speed-limit-tests

The UDOT Director noted that there was no increase in the number of

accidents on Interstate 15 But what happens in the event of an accident

when the speed limits are higher and drivers are driving at higher speeds and

two objects collide at this higher speed However no increase in the number

of accidents is not the same as no increase in fatalities due to the higher

speeds When accidents do occur do fatalities increase

Likewise in California when the speed limit went up from 55 mph to 65

mph in 1995 (after repeal of NMSL) fewer deaths were reported in 1998

compared to the peak year of 1979 or even 1987 Again the explanation

seems to be that motorists were already speeding when the limit was 55 mph

and that increasing the speed limit did not change driver behavior in any

significant way

httparticlessfgatecom1998-11-02news17735730_1_speed-limits-mph-

limit-death-rate

The National Motorists Association (NMA) a group which advocates higher

speed limits emphasizes the importance of considering fatality rates as

opposed to the raw fatalities The argument used is that fatality rates based

on the fatality per 100 million VMT is the legitimate way to look at the data

Page 27 of 45

This is a never ending debate Historically speaking fatality rates have been

going down ever since the compilation of traffic accidents data began Table

A1 in the appendix of a recent report by NHTSA (see link below) has highway

fatality rate data going back 1921

httpwww-nrdnhtsadotgovPubs811346pdf see appendix page 31

httpwwwmotoristsorgspeed-limitstruth

httpwwwmotoristsorgothercrash-data

httpwwwraisethespeedlimitorgmythshtml

httpwwwcatoorgpubspaspa346pdf

According to Stephen Moore of the Cato Institute (see last of the links above)

―All measures of highway safety show improvement not more deaths and

injuries since 1995 Despite the fact that 33 states raised their speed limits

immediately after the repeal of the mandatory federal speed limit the NHTSA

reported last October that the traffic death rate dropped to a record low level

in 1997lsquo Moreover the average fatality rate even fell in the states that raised

their speed limits

63 The Fatality rate Is it a reliable metric

In 1921 with fewer fatalities and fewer miles driven and the first year for

which the fatality rate could be computed the rate was 2408 It was down to

1479 in 1931 but the number of deaths had climbed to 31963 more than

double the 1921 absolute fatality number of 13253 It had dropped to 550 in

1966 the year of the highly publicized Congressional hearings but the

number of fatalities had climbed to 50984 in that fateful The Highway Safety

Act of 1966 ranks as one of the major acts of Congress and President

Johnson signed it saying that ―we have been tolerating a raging epidemic of

highway deathshellip see extract pasted below

httpwwwenotescommajor-acts-congresshighway-safety-act

Page 28 of 45

The act was motivated primarily by growing public concern over the rising number

of traffic fatalities in the United States Between 1960 and 1965 the annual number

of traffic fatalities increased by nearly thirty percent As President Lyndon B

Johnson stated at the signing of the act on September 9 1966 we have tolerated

a raging epidemic of highway death which has killed more of our youth than all

other diseases combined Through the Highway Safety Act we are going to find out

more about highway diseasemdashand we aim to cure it

Nonetheless highways fatalities continued to increase until the Arab oil

embargo of 1973 led to the NMSL of 55 mph all across the USA Do we just

ignore this undeniable historical record and focus only on the declining fatality

rate as the NMA and other proponents of higher speed limits seem to argue

(see links above)

The misleading nature of using fatality rates (per 100 M VMT) alone is also

obvious if one considers fatality data for individual states Take for example

the state of Montana which seems to have experienced no increase in

fatalities after repeal of NMSL

httpwww-nrdnhtsadotgovdepartmentsnrd-

30ncsaSTSI30_MT200930_MT_2009htm

For the period 2005-2009 the absolute number of fatalities for Montana

varied between a high of 277 in 2007 to a low of 229 in 2009 The fatality

rates per 100 M VMT on the other hand varied from a high of 245 for 2007

to a low of 201 for 2009 The corresponding US fatality rates varied from

136 to 114 Is the higher number for the fatality rate for Montana compared

to USA good or bad Likewise fatality rate per 100000 of population was

much higher for Montana than the US as a whole

This again highlights the pitfalls of using simple ratios to assess fatality statistics

without a full analysis of the underlying trends We will discuss this point

separately

As shown already the continuous decline in the fatality rate is a mathematical

artifact and essentially overlooks the unmistakable positive correlation

between the variables x and y of the type y = hx + c which becomes obvious

Page 29 of 45

only when we prepare the x-y scatter graph The ratio yx = h + (cx) can

decrease with increasing x (VMT) and increasing y (fatalities) since the

intercept c has a positive value when we consider only data spanning a short

period (such as 1994-2009 of more relevance to the current situation)

The debate between fatality rates and absolute number of fatalities is an

unending one A few years ago the Wall Street Journal carried an article

which was entitled (or something close) ―Unemployments rate in Ohio are

going down but why is the number of unemployed increasing The reason is

the same The graph of the number of unemployed (y) versus the number in

the labor market (x) is linear with a positive slope h and a positive intercept c

So the unemployment rate computed using the ratio yx keeps going down

year after year although the number unemployed keeps increasing Is it a

good thing that the unemployment rate is going down when more people

seem to be unable to find gainful unemployment

Or consider the situation with cancer death rates This too has been going

down in recent years but the actual number of cancer-related deaths has not

declined in any significant way Is it good that cancer death rates are going

down In all these situations the researchers or the socio-econo-politico

analysts involved in analyzing the trends in the data have failed to consider

the underlying x-y relation describing each problem

Hence it appears that the debate on the effect of increased speed limits

should not be focused on only the fatality rates (which have been decreasing

and proponents of higher speed limits cite this in their arguments) or even the

absolute number of fatalities (which has been the focus here) but on the

relationship between speed and the number of fatal crashes and the number

of fatalities within each speed segment (see Table 3 and also Figure 4)

Unfortunately details of number of fatalities and the number of fatal crashes

at each speed limit are not available even from NHTSA for detailed study

When a crash does occur (it is immaterial how many miles were driven) the

speed of the driver and vehicle design and engineering including safety

devices in place (seat belts airbags other impact absorbing technologies)

Page 30 of 45

determine if the occupants(s) will be killed One cannot argue that speed

does NOT kill That would be an absolute denial of the laws of physics

Studies show that setting the speed limit at the 85th percentile in any given

zone (this is the speed at or below which 85 of drivers are observed to

travel in traffic engineering studies) is the safest speed limit The majority of

drivers try to obey the posted speed limit while a few choose to drive at a

speed they consider is safe and prudent These are also perhaps the most

vociferous advocates of higher speed limits It is this tension caused due to

differences in speeds that leads to tailgating improper passing reckless

driving weaving from lane to lane and ultimately crashes and deaths in some

unfortunate cases

httpblogmotoristsorgspeed-limits-slower-safer

MARK TAYLOR

ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New

Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried

to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways

into a tree Alerts to slow down had been posted since this was a high accident area but the driver

probably did not pay attention

64 Other factors

Many other factors besides speed no doubt affect highway fatalities The

vehicles of the 21st century are very different from the vehicles of the mid 20th

Page 30 of 45

determine if the occupants(s) will be killed One cannot argue that speed

does NOT kill That would be an absolute denial of the laws of physics

Studies show that setting the speed limit at the 85th percentile in any given

zone (this is the speed at or below which 85 of drivers are observed to

travel in traffic engineering studies) is the safest speed limit The majority of

drivers try to obey the posted speed limit while a few choose to drive at a

speed they consider is safe and prudent These are also perhaps the most

vociferous advocates of higher speed limits It is this tension caused due to

differences in speeds that leads to tailgating improper passing reckless

driving weaving from lane to lane and ultimately crashes and deaths in some

unfortunate cases

httpblogmotoristsorgspeed-limits-slower-safer

MARK TAYLOR

ANOTHER LOST A man was killed when his 4WD drive hit a tree east of Morrinsville (in New

Zealand) on Monday May 30 2011 The driver lost control of the vehicle on a bend probably tried

to correct his mistake and put the car into a ―yaw causing it to leave the road and smash sideways

into a tree Alerts to slow down had been posted since this was a high accident area but the driver

probably did not pay attention

64 Other factors

Many other factors besides speed no doubt affect highway fatalities The

vehicles of the 21st century are very different from the vehicles of the mid 20th

Page 31 of 45

century Technological innovations such as improvements in vehicle design

and engineering have greatly increased crash worthiness of vehicles even at

high speeds Environmental factors such as the weather also contribute to

accidents but not necessarily to increased fatalities Drivers actually tend to

slow down instinctively during adverse weather conditions (rain snow storms

etc) and although such weather may contribute to increased accidents the

lower speeds actually reduce fatalities

Yes technology has changed fundamentally from 1966 Drivers today are

more distracted by their cellmobile phone conversations (and also built-in

phones in luxury models) and text messaging than the drivers of the pre-1966

era High end cars now have many multimedia and internet features Again a

careful observation (even personal experience by the author) suggests that

such distracted drivers actually tend to (instinctively) drive more slowly and

hold up the traffic Perhaps such behavior leads to an increase in the number

of accidents but it does not necessarily lead to an increase in the number of

accident-related fatalities

Much talked about technological innovations such as automatic collision

avoidance systems and sensors (on the sides of vehicles) can indeed detect

vehicles in the front and neighboring lanes Furthermore vehicle-to-vehicle

communication systems vehicle-to-infrastructure communication systems

can no doubt avoid collisions and accidents Again such collision avoidance

systems work and are effective entirely because they automatically reduce

vehicle speeds - even if one of the offending vehicles is being at a super

high speed Also it must be remembered that such futuristic systems have

not yet been implemented widely nor can they be implemented widely since

the large majority of vehicles on the road are NOT luxury models Advanced

safety features come with a price and not all drivers can afford to pay that

price and ―buy that ―additional safety

Ultimately it is the laws of physics that govern what will happen when two or

more vehicles collide or even when a single vehicle collides with a stationary

infrastructural object (a bridge a wall a building or some impediment on the

road) The lower the number of crashes the lower the number of fatalities as

revealed by the 1994-2009 data graphed in Figure 5 The higher the speed of

Page 32 of 45

the object or objects that are involved in a collision the higher the kinetic

energy K that must be absorbed andor dissipated Increasing the posted

speed limit only increases the energy that must be absorbed when a crash

does occur This ultimately is the most important criterion determining the

number of fatalities

The kinetic energy increases as the square of the speed being given by the

well-known formula K = frac12 mv2 where m is the mass of the vehicle (in

laypersonlsquos language m increases directly with vehicle weight) and v is the

speed For the same vehicle mass an increase in the speed from 55 mph to

85 mph increases the kinetic energy K by a factor of 239 or roughly a 250

increase in the kinetic energy that must be absorbed in a collision

Ideally speaking the kinetic energy of the colliding object(s) is absorbed by

the vehicle infrastructure (a sturdy space frame the engine other vehicle

components etc) andor the surroundings However in the unfortunate

cases where this kinetic energy must be absorbed by the vehicle occupant(s)

the result is severe life-altering injuries andor death An unequivocal

relationship between an increase in vehicle speeds and fatal accidents can

be demonstrated by a careful examination of available traffic fatality data

This is a more involved discussion and is not the purpose of this short

communication These topics are no doubt very politically charged with many

social legal and financial implications with each interest group favoring a

different conclusion Nonetheless we cannot escape the laws of physics as

they govern the fundamental need to absorb higher and higher values of the

kinetic energy K with increasing vehicle speeds This same point is also

emphasized by Dr Friedman of the University of Illinois Chicago (see earlier

discussion)

Speed kills because of these energy transfer considerations and there can be

no doubt about it

Innovative 21st century solutions to speed management on the highways

such as strict enforcement of speed limits minimizing speed dispersion

(difference between speeds at which different drivers travel) while using

cameras to track the 15 of drivers who willfully violate the speed limit and

Page 33 of 45

create hazardous driving conditions is certainly recommended (Recall that

the optimum recommended speed limit is at or below which 85 of all drivers

travel ndash a policy also supported by NMA) Even on this score however the

results are confounding if we consider the Australian experience

httpwwwthenewspapercomnews282840asp

Up until 2007 there was no speed limit in the Northern Territory of

Australia Imposing a speed limit 130 kmph (80 mph) on some areas and

110 kmph (68 mph) in some others actually increased the number of deaths

The death toll in 2006 when there was no speed limit in this region was 44

and went up to 75 in 2009 see data table in link below

httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf

Furthermore it appears that installation of cameras to enforce speed limits

has proved to be a hazardous distraction to drivers and deaths actually

began to skyrocket between 2005 and 2007 in all Australian roadways

The main purpose here is to sound a cautionary note amid renewed attempts

in many states across the US to increase the speed limits on our highways by

calling attention to the historical facts regarding the ―epidemic levels of

highway traffic fatalities that engaged our national attention in the fateful year

of 1966 The graphical representation of the traffic fatality data in Figures 1

to 5 tells its own story

Indeed it would be tragic if highway-accident-related fatalities were to start

increasing once again and reach the historically high level that was last seen

in 1972 the year before the Arab oil embargo of 1973

Page 32 of 45

the object or objects that are involved in a collision the higher the kinetic

energy K that must be absorbed andor dissipated Increasing the posted

speed limit only increases the energy that must be absorbed when a crash

does occur This ultimately is the most important criterion determining the

number of fatalities

The kinetic energy increases as the square of the speed being given by the

well-known formula K = frac12 mv2 where m is the mass of the vehicle (in

laypersonlsquos language m increases directly with vehicle weight) and v is the

speed For the same vehicle mass an increase in the speed from 55 mph to

85 mph increases the kinetic energy K by a factor of 239 or roughly a 250

increase in the kinetic energy that must be absorbed in a collision

Ideally speaking the kinetic energy of the colliding object(s) is absorbed by

the vehicle infrastructure (a sturdy space frame the engine other vehicle

components etc) andor the surroundings However in the unfortunate

cases where this kinetic energy must be absorbed by the vehicle occupant(s)

the result is severe life-altering injuries andor death An unequivocal

relationship between an increase in vehicle speeds and fatal accidents can

be demonstrated by a careful examination of available traffic fatality data

This is a more involved discussion and is not the purpose of this short

communication These topics are no doubt very politically charged with many

social legal and financial implications with each interest group favoring a

different conclusion Nonetheless we cannot escape the laws of physics as

they govern the fundamental need to absorb higher and higher values of the

kinetic energy K with increasing vehicle speeds This same point is also

emphasized by Dr Friedman of the University of Illinois Chicago (see earlier

discussion)

Speed kills because of these energy transfer considerations and there can be

no doubt about it

Innovative 21st century solutions to speed management on the highways

such as strict enforcement of speed limits minimizing speed dispersion

(difference between speeds at which different drivers travel) while using

cameras to track the 15 of drivers who willfully violate the speed limit and

Page 33 of 45

create hazardous driving conditions is certainly recommended (Recall that

the optimum recommended speed limit is at or below which 85 of all drivers

travel ndash a policy also supported by NMA) Even on this score however the

results are confounding if we consider the Australian experience

httpwwwthenewspapercomnews282840asp

Up until 2007 there was no speed limit in the Northern Territory of

Australia Imposing a speed limit 130 kmph (80 mph) on some areas and

110 kmph (68 mph) in some others actually increased the number of deaths

The death toll in 2006 when there was no speed limit in this region was 44

and went up to 75 in 2009 see data table in link below

httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf

Furthermore it appears that installation of cameras to enforce speed limits

has proved to be a hazardous distraction to drivers and deaths actually

began to skyrocket between 2005 and 2007 in all Australian roadways

The main purpose here is to sound a cautionary note amid renewed attempts

in many states across the US to increase the speed limits on our highways by

calling attention to the historical facts regarding the ―epidemic levels of

highway traffic fatalities that engaged our national attention in the fateful year

of 1966 The graphical representation of the traffic fatality data in Figures 1

to 5 tells its own story

Indeed it would be tragic if highway-accident-related fatalities were to start

increasing once again and reach the historically high level that was last seen

in 1972 the year before the Arab oil embargo of 1973

Page 33 of 45

create hazardous driving conditions is certainly recommended (Recall that

the optimum recommended speed limit is at or below which 85 of all drivers

travel ndash a policy also supported by NMA) Even on this score however the

results are confounding if we consider the Australian experience

httpwwwthenewspapercomnews282840asp

Up until 2007 there was no speed limit in the Northern Territory of

Australia Imposing a speed limit 130 kmph (80 mph) on some areas and

110 kmph (68 mph) in some others actually increased the number of deaths

The death toll in 2006 when there was no speed limit in this region was 44

and went up to 75 in 2009 see data table in link below

httpwwwthenewspapercomrlcdocs2009au-ntroadtollpdf

Furthermore it appears that installation of cameras to enforce speed limits

has proved to be a hazardous distraction to drivers and deaths actually

began to skyrocket between 2005 and 2007 in all Australian roadways

The main purpose here is to sound a cautionary note amid renewed attempts

in many states across the US to increase the speed limits on our highways by

calling attention to the historical facts regarding the ―epidemic levels of

highway traffic fatalities that engaged our national attention in the fateful year

of 1966 The graphical representation of the traffic fatality data in Figures 1

to 5 tells its own story

Indeed it would be tragic if highway-accident-related fatalities were to start

increasing once again and reach the historically high level that was last seen

in 1972 the year before the Arab oil embargo of 1973

Page 34 of 45

Conclusions

1 The graphical representation of the highway fatality data and the brief

summary of the historical facts of traffic safety legislation suggest that

recent attempts to increase the speed limits by various states (notably

Texas) may be misguided The distinct peak in the highway fatalities

observed in these graphs is highly alarming This appears to be related to

the enactment of the National Maximum Speed Limit (NSML) in 1974

following the 1973 Arab oil embargo Although NSML was motivated by a

desire to reduce gasoline consumption an unintended benefit might have

been a dramatic reduction in fatalities The fundamental reasons for the

peak in the fatalities-VMT curve must be examined carefully without

political posturing

2 The widely used fatality rate fatalities per 100 M vehicle miles traveled

has been declining since 1921 the first year for which a fatality rate could

be computed and has now reached a historical low The absolute number

of fatalities on the other hand was increasing in the 1950s and 1960s at

an alarming rate and the public outcry that ensued led to the highly

publicized Congressional hearing of 1966 and the subsequent traffic safety

legislations The fatality rate has been decreasing even in the most recent

15-year period (1994-2009) again with increasing fatalities although less

dramatically Thus it appears that fatality rate calculation based on vehicle

miles traveled (VMT) might not be a reliable indicator of the underlying

dynamics in the fatality trends

3 More detailed compilation of number of fatalities and the number of fatal

crashes within each speed limit segment is required to better understand

the effect of increasing speed limits on highway fatalities (and also fatality

rates) Such data is already available and is being compiled at the local

city and county levels in all jurisdictions and only needs to be reorganized

to highlight the effect of (posted) speed limits on the number of crashes

and fatalities This will require some minor rewriting and revisions to the

chapters named ―Crashes and ―States in the annual NHTSA reports

Page 35 of 45

Analysis of the fatalities-crashes data for several years with various

speed limits will be more revealing and meaningful than the current

fatality rates analysis and will be discussed separately in a follow up

report

4 One should not be lulled by the fact that vehicles of the 21st century are

now equipped with advanced safety features not available in the 1950s

and the 1960s In spite of these safety features the laws of physics dictate

that the higher the speed the higher kinetic energy of the colliding objects

and hence the greater the risk indeed near certainty of fatalities in a

higher speed collision compared to a lower speed one

5 The higher the speed at which the vehicle that is involved in a crash is

traveling the higher the kinetic energy that must be absorbed andor

dissipated without affecting the occupant(s) to avoid serious injuries andor

death This was true in the 1950s and the 1960s and will continue to be

true in the 21st century as well

Speed Kills for this just reason

6 It appears that higher fuel economies and reduced

highway fatalities were the twin societal benefits of 55

mph adopted after 1973 If so the current attempts to

increase the speed limits appear to be in conflict with

other important societal objectives

Page 36 of 45

Table 1 Annual US Street amp Highway

Fatalities from 1957

Year

Fatalities

Vehicle Miles

(millions)

Rate100M Vehicle Miles

1957 38702 646915 598

1958 36981 664915 556

1959 37910 700478 541

1960 38137 718845 531

1961 38091 737535 516

1962 40804 766852 532

1963 43564 805423 541

1964 47700 846500 563

1965 49163 887640 554

1966 51524 927915 555

1967 51559 965132 534

1968 53831 1019726 528

1969 55032 1066108 516

1970 53672 1114098 482

1971 53761 1183524 454

1972 55704 1264614 440

1973 55113 1316207 419

1974 46078 1282790 359

1975 45500 1330074 342

1976 45523 1402380 325

1977 47878 1467027 326

1978 50331 1544704 326

1979 51103 1529133 334

1980 51091 1527295 335

1981 49301 1552803 317

1982 43945 1595010 276

1983 42589 1652788 258

1984 44257 1720269 257

1985 43795 1774179 247

Page 37 of 45

1986 46056 1835000 251

1987 46385 1921000 241

1988 47093 2026000 232

1989 45555 2107040 216

1990 44529 2147501 207

1991 41162 2172214 189

1992 39235 2239828 175

1993 40115 2296585 175

1994 40676 2359984 172

1995 41798 2422696 173

1996 41907 2485848 169

1997 41967 2560373 164

Data from Federal Highway Administration

Source httpwwwpublicpurposecomhwy-fatal57+htm

Telephone +16186328507 - Facsimile +16186328538

WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA

Page 35 of 45

Analysis of the fatalities-crashes data for several years with various

speed limits will be more revealing and meaningful than the current

fatality rates analysis and will be discussed separately in a follow up

report

4 One should not be lulled by the fact that vehicles of the 21st century are

now equipped with advanced safety features not available in the 1950s

and the 1960s In spite of these safety features the laws of physics dictate

that the higher the speed the higher kinetic energy of the colliding objects

and hence the greater the risk indeed near certainty of fatalities in a

higher speed collision compared to a lower speed one

5 The higher the speed at which the vehicle that is involved in a crash is

traveling the higher the kinetic energy that must be absorbed andor

dissipated without affecting the occupant(s) to avoid serious injuries andor

death This was true in the 1950s and the 1960s and will continue to be

true in the 21st century as well

Speed Kills for this just reason

6 It appears that higher fuel economies and reduced

highway fatalities were the twin societal benefits of 55

mph adopted after 1973 If so the current attempts to

increase the speed limits appear to be in conflict with

other important societal objectives

Page 36 of 45

Table 1 Annual US Street amp Highway

Fatalities from 1957

Year

Fatalities

Vehicle Miles

(millions)

Rate100M Vehicle Miles

1957 38702 646915 598

1958 36981 664915 556

1959 37910 700478 541

1960 38137 718845 531

1961 38091 737535 516

1962 40804 766852 532

1963 43564 805423 541

1964 47700 846500 563

1965 49163 887640 554

1966 51524 927915 555

1967 51559 965132 534

1968 53831 1019726 528

1969 55032 1066108 516

1970 53672 1114098 482

1971 53761 1183524 454

1972 55704 1264614 440

1973 55113 1316207 419

1974 46078 1282790 359

1975 45500 1330074 342

1976 45523 1402380 325

1977 47878 1467027 326

1978 50331 1544704 326

1979 51103 1529133 334

1980 51091 1527295 335

1981 49301 1552803 317

1982 43945 1595010 276

1983 42589 1652788 258

1984 44257 1720269 257

1985 43795 1774179 247

Page 37 of 45

1986 46056 1835000 251

1987 46385 1921000 241

1988 47093 2026000 232

1989 45555 2107040 216

1990 44529 2147501 207

1991 41162 2172214 189

1992 39235 2239828 175

1993 40115 2296585 175

1994 40676 2359984 172

1995 41798 2422696 173

1996 41907 2485848 169

1997 41967 2560373 164

Data from Federal Highway Administration

Source httpwwwpublicpurposecomhwy-fatal57+htm

Telephone +16186328507 - Facsimile +16186328538

WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA

Page 36 of 45

Table 1 Annual US Street amp Highway

Fatalities from 1957

Year

Fatalities

Vehicle Miles

(millions)

Rate100M Vehicle Miles

1957 38702 646915 598

1958 36981 664915 556

1959 37910 700478 541

1960 38137 718845 531

1961 38091 737535 516

1962 40804 766852 532

1963 43564 805423 541

1964 47700 846500 563

1965 49163 887640 554

1966 51524 927915 555

1967 51559 965132 534

1968 53831 1019726 528

1969 55032 1066108 516

1970 53672 1114098 482

1971 53761 1183524 454

1972 55704 1264614 440

1973 55113 1316207 419

1974 46078 1282790 359

1975 45500 1330074 342

1976 45523 1402380 325

1977 47878 1467027 326

1978 50331 1544704 326

1979 51103 1529133 334

1980 51091 1527295 335

1981 49301 1552803 317

1982 43945 1595010 276

1983 42589 1652788 258

1984 44257 1720269 257

1985 43795 1774179 247

Page 37 of 45

1986 46056 1835000 251

1987 46385 1921000 241

1988 47093 2026000 232

1989 45555 2107040 216

1990 44529 2147501 207

1991 41162 2172214 189

1992 39235 2239828 175

1993 40115 2296585 175

1994 40676 2359984 172

1995 41798 2422696 173

1996 41907 2485848 169

1997 41967 2560373 164

Data from Federal Highway Administration

Source httpwwwpublicpurposecomhwy-fatal57+htm

Telephone +16186328507 - Facsimile +16186328538

WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA

Page 37 of 45

1986 46056 1835000 251

1987 46385 1921000 241

1988 47093 2026000 232

1989 45555 2107040 216

1990 44529 2147501 207

1991 41162 2172214 189

1992 39235 2239828 175

1993 40115 2296585 175

1994 40676 2359984 172

1995 41798 2422696 173

1996 41907 2485848 169

1997 41967 2560373 164

Data from Federal Highway Administration

Source httpwwwpublicpurposecomhwy-fatal57+htm

Telephone +16186328507 - Facsimile +16186328538

WENDELL COX CONSULTANCY P O Box 841 - Belleville IL 62269 USA

Page 38 of 45

Fatality data for 1921-1982 compiled by NHTSA

Year

VMT

(Millions)

VMT

(Billions)

Fatalities

Fatality rate

per 100 M VMT

1921 55027 5503 13253 241 1922 67697 6770 14859 219 1923 84995 8500 17870 210 1924 104838 10484 18400 176 1925 122346 12235 20771 170 1926 140735 14074 22194 158 1927 158453 15845 24470 154 1928 172856 17286 26557 154 1929 197720 19772 29592 150 1930 206320 20632 31204 151 1931 216151 21615 31963 148 1932 200517 20052 27979 140 1933 200642 20064 29746 148 1934 215563 21556 34240 159 1935 228568 22857 34494 151 1936 252128 25213 36126 143 1937 270110 27011 37819 140 1938 271177 27118 31083 115 1939 285402 28540 30895 108 1940 302188 30219 32914 109 1941 333612 33361 38142 114 1942 268224 26822 27007 101 1943 208192 20819 22727 109 1944 212713 21271 23165 109 1945 250173 25017 26785 107 1946 340880 34088 31874 94 1947 370894 37089 31193 84 1948 397957 39796 30775 77 1949 424461 42446 30246 71 1950 458246 45825 33186 72 1951 491093 49109 35309 72

1952 513581 51358 36088 70

Page 39 of 45

1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28

Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in

2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31

httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R

elated20Fatal20Motor20Vehicle20Traffic20Crashespdf

Page 39 of 45

1953 544433 54443 36190 66 1954 561963 56196 33890 60 1955 605646 60565 36688 61 1956 627843 62784 37965 60 1957 647004 64700 36932 57 1958 664653 66465 35331 53 1959 700480 70048 36223 52 1960 718762 71876 36399 51 1961 737421 73742 36285 49 1962 766734 76673 38980 51 1963 805249 80525 41723 52 1964 846298 84630 45645 54 1965 887812 88781 47089 53 1966 925899 92590 50894 55 1967 964005 96401 50724 53 1968 1015869 101587 52725 52 1969 1061791 106179 53543 50 1970 1109724 110972 52627 47 1971 1178811 117881 52542 45 1972 1259786 125979 54589 43 1973 1313110 131311 54052 41 1974 1280544 128054 45196 35 1975 1327664 132766 44525 34 1976 1402380 140238 45523 32 1977 1467027 146703 47878 33 1978 1544704 154470 50331 33 1979 1529133 152913 51093 33 1980 1527295 152730 51091 33 1981 1555308 155531 49301 32 1982 1595010 159501 43945 28

Source Analysis of Significant Decline in Motor Vehicle Traffic Fatalities in

2008 httpwww-nrdnhtsadotgovPubs811346pdf see Table A1 page 31

httpwwwcidarmymildocumentsSafetyCurrent20FocusSpeeding20R

elated20Fatal20Motor20Vehicle20Traffic20Crashespdf

Page 40 of 45

Acknowledgements

The author is grateful for thoughtful comments provided by friends and colleagues

with whom this document was shared via email prior to it being uploaded as a

publicly available document for wider dissemination and study The comments

offered by Prof Subra Ganesan of Oakland University Electrical and Computer

Engineering Department are reproduced with permission in their entirety

About the author

The author obtained his Masterrsquos (S M) and Doctoral (Sc D) degrees in Materials Engineering

from the Massachusetts Institute of Technology Cambridge USA He then spent his entire

professional career at leading US research institutions (MIT NASA Case Western Reserve

University and General Motors R amp D Center in Warren MI) He holds four patents in advanced

materials processing has co-authored two books and has published several scientific papers in

leading peer-reviewed international journals His expertise includes developing simple

mathematical models to explain the behavior of complex systems He can be reached by email at

vlaxmananhotmailcom

Page 41 of 45

Please Buckle Up

httpwwwlakecountypublichealthorgindexphpbuckle-up-montana

Public Awareness

Respect the Cage Exhibit

The Department of Transportation hopes that showing the reality of the crash will reduce traffic

fatalities A crushed car crash dummies and a sobering message ndash all part of the ―Respect The

Cage exhibit that is traveling across Montana The exhibit sponsored by the Montana Department

of Transportation stopped in Ronan on November 6th and is aimed at raising awareness about the

importance of wearing seat belts

The car in the exhibit was in an actual wreck many years ago

the passenger in the vehicle died because he was not wearing a

seat belt the driver who was wearing his seat belt survived

Montanarsquos likeliest crash fatality scenario

A Pickup

A Rural road

And Seat belts that

arenrsquot used

Page 42 of 45

Occupants of pickups are less likely to wear seat belts and pickups are more likely to

roll over than passenger cars

Seat belts reduce the risk of death by 60 percent in pickups and SUVs

In Montana from 2006-2008 81 of those killed in a crash while riding in a pickup were not wearing seat belts

In Montana pickups make up 401 of the vehicle population

For more information on Respect the Cage click here

Page 43 of 45

Appendix 1

Lack of seat belts leading cause of Louisiana highway deaths

1251 AM May 28 2011 |

Written by Adam Duvernay

Crashes involving unbuckled motorists were the leading cause of highway fatalities

in Louisiana last year and cost $9888 million according to recent reports The

Louisiana Highway Safety Commission reported 59 percent of vehicle occupants

killed in Louisiana crashes last year mdash about one in four mdash werent wearing seat

belts

httpwwwshreveporttimescomarticle20110528NEWS01105280354Lack-seat-

belts-leading-cause-La-highway-deathsodyssey=tab|topnews|text|FRONTPAGE

Crash bull Stats Published by NHTSAlsquos National Center for Statistics and Analysis 1200 New Jersey Avenue SE Washington DC 20590

DOT HS 811 451

Early Estimate of Motor Vehicle Traffic Fatalities in 2010

httpwww-nrdnhtsadotgovPubs811451pdf

Summary

A statistical projection of traffic fatalities in 2010 shows that an estimated 32788

people died in motor vehicle traffic crashes This represents a decline of about 3

percent as compared to the 33808 fatalities in 2009 as shown in Table 1 If these

projections are realized fatalities will be lowest on record (since 1949)

Traffic Safety Facts Overview 2009 Data

httpwww-nrdnhtsadotgovPubs811392pdf

In 2009 33808 people were killed in the estimated 5505000 police-reported

motor vehicle traffic crashes 2217000 people were injured and 3957000

crashes involved property damage only Compared to 2008 this is a 10-

percent decrease in the number of fatalities and a 5-percent decrease in the

Page 44 of 45

number of police-reported motor vehicle traffic crashes people injured and

crashes involving property damage

An average of 93 people died each day in motor vehicle crashes in 2009 mdash

an average of one every 16 minutes

Traffic Safety Facts Overview 2008 Data

httpwww-nrdnhtsadotgovPubs811162pdf

In 2008 37261 people were killed in the estimated 5811000 police-reported

motor vehicle traffic crashes 2346000 people were injured and 4146000

crashes involved property damage only

Some comments and Feedback

The following comments were received from Prof Ganesan after his review of the

first draft of this document It was subsequently revised thanks to this input to

address some of the very important issues raised here

Dear Laxman

The write up is not enough

You are emphasizing that the speed limit reduces the fatal accidents (comparing 1966

to 2000 accident numbers)

Can you also add a few sentences why the number is decreasing from 1980 to 2000

values (May be due to better design of vehicles)

Can you say anything about the fuel consumption with the speed for any typical

vehicle in 2011 or 2010 (do not consider the fatalities issue)

Probably a speed between 55 and 60 mph gives a better mileage If so this is a

compelling reason to keep the speed limit low But cars probably can be tuned to

give better mileage at any high speed also

Page 45 of 45

Weather is also a major factor in fatal accidents Speed limit may be kept low during

winter and kept higher in summer Give your comments on this too

Driver distractions can cause more accidents Now cars have many multimedia and

internet features Automatic collision avoidance systems and sensors on the sides can

detect vehicles in the front and neighboring lanes and it can automatically decrease

speed even if the driver speeds at super high speeds

Give some comments on this too There is also Vehicle to Vehicle communications

vehicle to infrastructure communications and they can avoid collisions and accidents

Technology has changed from 1966 I cannot agree with you on the speed limit

without any discussion on the above and other factors

Have a great day

Subra Ganesan

Professor Subramaniam Ganesan

Director Real Time amp DSP Lab

Electrical and Computer Engineering Department

2200 Squirrel Road Dodge Hall Room 105

Oakland University Rochester MI 48309 USA

Phone 248 370 2206 Fax 248 370 4633

wwwsecsoaklandedu~ganesan

IEEE Distinguished Visiting Speaker (2005-2009) Coordinator

IEEE SEM CS chapter Chair Region 4 and CS Society Board member

SAE ASEE ACM member