Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
57 1. As progress has been made to increase SBU, there have been declining impacts (in terms of observed usage) asso- ciated with daytime programs implemented to increase use (Glassbrenner, 2005; Nichols and Jones, under review). A P P E N D I X C Issues and Findings Regarding Nighttime SBU and Enforcement 0 20 40 60 80 100 '79 '81 '83 '85 '87 '89 '91 '93 '95 '97 '99 '01 '03 '05 Year Pe rc en t U sa ge Initial Laws Upgrades and Mobilizations 0 20 40 60 80 100 Us ag e (% ) OR MI CA WA MD TX HI NM NV Observed Use FARS Use 2. States with high usage rates have much lower rates among fatally injured occupants. For example, the nine states with 90%+ usage have a median FARS rate of only 54% (range: 47% to 68%). Source: FARS. 3. One reason why FARS use is lower than observed use is that occupants with the highest risk of being involved in a serious crash are least likely to buckle up (e.g., youth, males, alcohol-positive drivers and passengers, occu- pants of pickup trucks, drivers with past violations and/or crashes, etc.). 4. High-risk occupants are relatively more prevalent during late-night hours, when there is little or no publicized en- forcement of belt laws. Statewide observational surveys measure only daytime use, usually immediately following a national CIOT mobilization. 5. There is a strong relationship between the presence of alcohol and nonuse of safety belts. Some relevant facts include: a. Nearly two-thirds of all persons killed in alcohol-related crashes are either the drinking drivers themselves (nearly half) or their passengers (about 17%).
b. Drinking drivers involved in fatal crashes are nearly three times more likely to be unbuckled (than non- drinking drivers) and unrestrained drivers are three times more likely to be drinking (than restrained drivers) (Subramanian, 2003). c. With the prevalence of males and young persons (as well as other high-risk groups) among both drinking and unrestrained drivers, it is apparent that there is much overlap among unrestrained and drinking driver target groups. Further, as the next figure shows, both problems peak late at night. This figure shows the number of unbuckled, alcohol- related deaths (solid line) by time of day, compared with the number of unbuckled, nonalcohol related deaths by time of day (dotted line). The combination of alcohol and nonuse, as it relates to fatalities, peaks at about 2 a.m. (Source: 2005 FARS data.) 58 d. HVE can increase nighttime usage and usage among high-risk occupants, particularly in conjunction with primary law upgrades. Some relevant findings include: i. Daytime enforcement may not affect nighttime usage to the same extent that it affects daytime usage (e.g., Grant, 1991; Vivoda et al., 2007). ii. Nighttime enforcement, particularly when aimed at late-night motorists and drinking drivers, can increase late-night usage (e.g., Malenfant and Van Houten, 1988; Wells et al., 1992). iii. Primary law upgrades have also been found to in- crease nighttime usage (e.g., Masten, 2007); usage among high-risk occupants (Eby et al., 2001); and usage among drinking drivers (Lange and Voas, 1998; Voas et al., in press). iv. Some studies have shown that HVE, complement- ing upgrades, has resulted in substantial increases in observed usage, even from very high baseline rates (e.g., Salzberg and Moffat, 2004). 0 100 200 300 400 500 600 12 :00 PM 2:0 0 P M 4:0 0 P M 6:0 0 P M 8:0 0 P M 10: 00 PM 12 :00 AM 2:0 0 A M 4:0 0 A M 6:0 0 A M 8:0 0 A M 10: 00 AM N um be r o f D ea th s Unbuckled with Positive BAC Unbuckled with Zero BAC