Insurance Institute for Highway Safety, 1005 North Glebe Road, Arlington, VA 22201, USA.
Accid Anal Prev. 2011 May;43(3):666-74. doi: 10.1016/j.aap.2010.10.010. Epub 2010 Nov 18.
Previous research has found that older driver fatal crash involvement rates per licensed driver declined substantially in the United States during 1997-2006 and declined much faster than the rate for middle-age drivers. The current study examined whether the larger-than-expected decline for older drivers extended to nonfatal crashes and whether the decline in fatal crash risk reflects lower likelihood of crashing or an improvement in survivability of the crashes that occur.
Trends in the rates of passenger vehicle crash involvements per 100,000 licensed drivers for drivers 70 and older (older drivers) were compared with trends for drivers ages 35-54 (middle-age drivers). Fatal crash information was obtained from the Fatality Analysis Reporting System for years 1997-2008, and nonfatal crash information was obtained from 13 states with good reporting information for years 1997-2005. Analysis of covariance models compared trends in annual crash rates for older drivers relative to rates for middle-age drivers. Differences in crash survivability were measured in terms of the odds of fatality given a crash each year, and the historical trends for older versus middle-age drivers were compared.
Fatal crash involvement rates declined for older and middle-age drivers during 1997-2008 (1997-2005 for the 13 state subsample), but the decline for drivers 70 and older far exceeded the decline for drivers ages 35-54 (37 versus 23 percent, nationally; 22 versus 1 percent, 13 states). Nonfatal injury crash involvement rates showed similarly larger-than-expected declines for older drivers in the 13 state subsample, but the differences were smaller and not statistically significant (27 percent reduction for older drivers versus 16 percent for middle-age drivers). Property-damage-only crash involvement rates declined for older drivers (10 percent) but increased for middle-age drivers (1 percent). In 1997, older drivers were 3.5 times more likely than middle-age drivers to die in police-reported crashes (6.2 versus 1.8 deaths per 1000 crashes), but this difference was reduced during the 9-year study period to 2.9 times, as the rate of older drivers dying in a crash declined (5.5 deaths per 1000 crashes in 2005) and the death risk remained relatively stable for middle-age drivers.
Contrary to expectations based on increased licensure and travel by older drivers, their fatal crash risk has declined during the past decade and has declined at a faster rate than for middle-age drivers. The decreased risk for older drivers appears to extend not only to nonfatal injury crashes but also to property-damage-only crashes, at least as reported to police in the 13 states included in the nonfatal injury analysis. Although insurance collision data suggest that overall crash risk of older drivers may not be changing relative to middle-age drivers, the current analysis indicates that the reduced fatality risk of older drivers reflects both less likelihood of being involved in a police-reported crash and greater likelihood that they will survive when they do crash.
先前的研究发现，1997 年至 2006 年间，美国年龄较大的驾驶员每持有驾照驾驶员的致命撞车事故参与率大幅下降，而且下降速度远快于中年驾驶员。本研究探讨了年龄较大的驾驶员的预期降幅是否扩展到非致命撞车事故，以及致命撞车事故风险的下降是否反映了撞车事故的可能性降低或发生撞车事故时的生存能力提高。
比较了 70 岁及以上驾驶员（老年驾驶员）每 100,000 名持照驾驶员乘用车撞车事故参与率的趋势与 35-54 岁驾驶员（中年驾驶员）的趋势。1997-2008 年从伤亡分析报告系统获得致命撞车事故信息，1997-2005 年从 13 个报告信息良好的州获得非致命撞车事故信息。协方差分析模型比较了老年驾驶员相对于中年驾驶员的年度撞车事故率趋势。每年发生撞车事故的情况下，死亡率的差异用死亡几率来衡量，并比较了老年驾驶员与中年驾驶员的历史趋势。
1997 年至 2008 年间（13 个州样本为 1997 年至 2005 年），老年和中年驾驶员的致命撞车事故参与率均有所下降，但 70 岁及以上驾驶员的降幅远远超过 35-54 岁驾驶员（全国 37%对 23%，13 个州 22%对 1%）。13 个州的样本中，老年驾驶员的非致命伤害撞车事故参与率也出现了类似的超出预期的下降，但降幅较小且无统计学意义（老年驾驶员下降 27%，中年驾驶员下降 16%）。仅造成财产损失的撞车事故参与率下降了 10%（老年驾驶员），但增加了 1%（中年驾驶员）。1997 年，老年驾驶员在警方报告的撞车事故中死亡的可能性是中年驾驶员的 3.5 倍（每 1000 次撞车事故中有 6.2 人死亡，而中年驾驶员为 1.8 人死亡），但在 9 年的研究期间，这一差距缩小到 2.9 倍，因为老年驾驶员的撞车事故死亡率下降（2005 年每 1000 次撞车事故中有 5.5 人死亡），而中年驾驶员的死亡风险相对稳定。
与基于老年驾驶员增加许可和出行的预期相反，他们的致命撞车事故风险在过去十年中有所下降，而且下降速度快于中年驾驶员。老年驾驶员的风险降低不仅适用于非致命伤害撞车事故，也适用于仅造成财产损失的撞车事故，至少在包括在非致命伤害分析中的 13 个州中向警方报告的情况如此。尽管保险碰撞数据表明，老年驾驶员的整体撞车事故风险相对于中年驾驶员可能没有变化，但目前的分析表明，老年驾驶员的死亡风险降低反映了他们参与警方报告的撞车事故的可能性降低，以及当他们确实发生撞车事故时生存的可能性增加。
