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Pages 22-41

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From page 22...
... 22 It appears from Chapter 5 that the very large drop in the number of traffic fatalities was the product of a relatively small decrease in exposure and a decline in the risk of a fatal crash and/or the risk of fatal injury, given the occurrence of a crash. That is, a decline in the risk of traffic fatalities can be the product of fewer crashes or better protection for people involved in a crash, or both.
From page 23...
... Trends in Contributing Factors 23 so trends should be reliable. The surveys have been conducted every 5 to 8 years.
From page 24...
... 24 Identification of Factors Contributing to the Decline of Traffic Fatalities in the United States from 2008 to 2012 they were fatally injured) , the reduction in traffic fatalities in 2008 and later was disproportionately a decline in the number of people under 26 who died in traffic crashes.
From page 25...
... Trends in Contributing Factors 25 6.2 Changes in Vehicles and Person Types Involved in Fatal Crashes This section provides perspective on the distribution of vehicles and persons involved in fatal crashes. Neither was particularly important in influencing the substantial decline in fatalities 2008–2012, but both reflected long-term trends that affect the overall level of traffic safety.
From page 26...
... 26 Identification of Factors Contributing to the Decline of Traffic Fatalities in the United States from 2008 to 2012 Most fatalities in traffic crashes are drivers of motor vehicles, and that did not change over the study period (Figure 6-6)
From page 27...
... Trends in Contributing Factors 27 represented of the overall number of fatalities, they would not significantly mitigate the downward trend for drivers and passengers. 6.3 Roadway Class and Type Earlier, Figure 4-2 showed that VMT generally increased each year from 2001 through 2007, dipped slightly in 2008 and then remained relatively flat through 2012.
From page 28...
... 28 Identification of Factors Contributing to the Decline of Traffic Fatalities in the United States from 2008 to 2012 would result in lower fatality rates per VMT overall. In addition, travel on Interstate-quality roads had significantly lower fatality rates than lower road classes in both urban and rural areas (Table 6-1)
From page 29...
... Trends in Contributing Factors 29 recession in absolute terms, as shown by a ratio to 2001 greater than 1.0 in Figure 6-10. The decline in urban areas began in 2007 and accelerated in 2008 through 2009, then stabilized before increasing slightly in 2012.
From page 30...
... 30 Identification of Factors Contributing to the Decline of Traffic Fatalities in the United States from 2008 to 2012 crush resistance, and fuel system impact protection; and crash avoidance, such as electronic stability control (ESC)
From page 31...
... Trends in Contributing Factors 31 vehicles less than 3 years old, 3 to 5 years, 6 to 10 years, and more than 10 years old. The right axis shows the overall average age of the vehicles.
From page 32...
... 32 Identification of Factors Contributing to the Decline of Traffic Fatalities in the United States from 2008 to 2012 those vehicles that were model year 2001 or later was computed. The data are displayed in Figure 6-13 (right axis)
From page 33...
... Trends in Contributing Factors 33 the range of observed safety-belt use across the years and among the states. It is not expected that the reader will be able to discern the pattern for any set of specific states; the data are shown in this way to convey that the overall trend was toward increased observed belt use, but also that there was significant variation among states and over time.
From page 34...
... 34 Identification of Factors Contributing to the Decline of Traffic Fatalities in the United States from 2008 to 2012 laws, typically categorized as primary or secondary enforcement laws, appeared as significant variables in state-level analyses of trends in fatal crashes and traffic fatalities. (For examples, see Grabowski and Morrisey 2004; Morrisey, Grabowski et al.
From page 35...
... Trends in Contributing Factors 35 Illinois, and New Hampshire) , while 19 had universal helmet laws, requiring motorcycle helmets for all riders.
From page 36...
... 36 Identification of Factors Contributing to the Decline of Traffic Fatalities in the United States from 2008 to 2012 The indexes for regulation of safety-belt use, alcohol, and motorcycle helmets were incorporated into models to measure the association with the overall level of traffic safety and their contribution to the drop in traffic fatalities 2008–2012. The models also included a measure of alcohol consumption, which directly reflects a critical element of actual driver behavior.
From page 37...
... Trends in Contributing Factors 37 turn, decreased exposure to fatal crashes and thus the number of traffic fatalities. Figure 4-2 showed a decline in VMT over the period, but it was likely not enough to explain the decline in fatalities by pure exposure.
From page 38...
... 38 Identification of Factors Contributing to the Decline of Traffic Fatalities in the United States from 2008 to 2012 to the recession that officially began in December 2007. Then the rate increased sharply to 9.6% in 2010 before declining again to 8.1% in 2012.
From page 39...
... Trends in Contributing Factors 39 6.8 Highway and Infrastructure The design, condition, and level of enforcement and related safety programs on the roadway system are critical elements in the level of traffic safety. Table 6-1 illustrated the variation of fatal crash rates across different roadway function classes.
From page 40...
... 40 Identification of Factors Contributing to the Decline of Traffic Fatalities in the United States from 2008 to 2012 Figure 6-22. Highway spending per mile of highway, 2001–2012.
From page 41...
... Trends in Contributing Factors 41 mile on capital expenditures, varying from a low of $11,100/highway mile (South Dakota) to $282,000/highway mile in Delaware.

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