Abstract：
BACKGROUND: Distracted driving has been linked to multiple driving decrements and is responsible for thousands of motor-vehicle fatalities annually. Most U.S. states have enacted restrictions on cellphone use while driving, the strictest of which prohibit any manual operation of a cellphone while driving. Illinois enacted such a law in 2014. To better understand how this law affected cellphone behaviors while driving, associations between Illinois\' handheld phone ban and self-reported talking on handheld, handsfree, and any cellphone (handheld or handsfree) while driving were estimated.
METHODS: Data from annual administrations of the Traffic Safety Culture Index from 2012-2017 in Illinois and a set of control states were leveraged. The data were cast into a difference-in-differences (DID) modeling framework, which compared Illinois to control states in terms of pre- to post-intervention changes in the proportion of drivers who self-reported the three outcomes. Separate models for each outcome were fit, and additional models were fit to the subset of drivers who talk on cellphones while driving.
RESULTS: In Illinois, the pre- to post-intervention decrease in the drivers\' probability of self-reporting talking on a handheld phone was significantly more extreme than that of drivers in control states (DID estimate -0.22; 95% CI -0.31, -0.13). Among drivers who talk on cellphones while driving, those in Illinois exhibited a more extreme increase in the probability of talking on a handsfree phone while driving than those control states (DID estimate 0.13; 95% CI 0.03, 0.23).
CONCLUSIONS: These results suggest that Illinois\' handheld phone ban reduced talking on handheld phones while driving among study participants. They also corroborate the hypothesis that the ban promoted substitution from handheld to handsfree phones among drivers who talk on the phone while driving.
CONCLUSIONS: These findings should encourage other states to enact comprehensive handheld phone bans to improve traffic safety.
METHODS: Data from annual administrations of the Traffic Safety Culture Index from 2012-2017 in Illinois and a set of control states were leveraged. The data were cast into a difference-in-differences (DID) modeling framework, which compared Illinois to control states in terms of pre- to post-intervention changes in the proportion of drivers who self-reported the three outcomes. Separate models for each outcome were fit, and additional models were fit to the subset of drivers who talk on cellphones while driving.
RESULTS: In Illinois, the pre- to post-intervention decrease in the drivers\' probability of self-reporting talking on a handheld phone was significantly more extreme than that of drivers in control states (DID estimate -0.22; 95% CI -0.31, -0.13). Among drivers who talk on cellphones while driving, those in Illinois exhibited a more extreme increase in the probability of talking on a handsfree phone while driving than those control states (DID estimate 0.13; 95% CI 0.03, 0.23).
CONCLUSIONS: These results suggest that Illinois\' handheld phone ban reduced talking on handheld phones while driving among study participants. They also corroborate the hypothesis that the ban promoted substitution from handheld to handsfree phones among drivers who talk on the phone while driving.
CONCLUSIONS: These findings should encourage other states to enact comprehensive handheld phone bans to improve traffic safety.
摘要：
背景：分心驾驶与多种驾驶减量有关，每年造成数千起机动车死亡。美国大多数州都颁布了对开车时使用手机的限制，其中最严格的规定禁止开车时手动操作手机。伊利诺伊州于2014年颁布了这样的法律。为了更好地了解这项法律如何影响开车时的手机行为，伊利诺伊州手持电话禁令和自我报告的手持通话之间的关联，免提,和任何手机（手持或免提），而驾驶估计。
方法：利用伊利诺伊州2012-2017年交通安全文化指数年度管理部门的数据和一组控制状态。数据被放入差异差异(DID)建模框架中，在干预前后自我报告三种结果的驾驶员比例变化方面，将伊利诺伊州与控制州进行了比较。每个结果的单独模型都是拟合的，以及其他型号适合在开车时用手机通话的驾驶员子集。
结果：在伊利诺伊州，与处于控制状态的驾驶员相比,干预前后驾驶员通过手持电话进行自我报告的概率下降明显更为极端(DID估计值-0.22;95%CI-0.31,-0.13).在开车时打电话的司机中，与对照组相比，伊利诺伊州的那些州在驾驶时使用免提电话通话的可能性增加了更多（DID估计0.13；95％CI0.03，0.23）。
结论：这些结果表明，伊利诺伊州的手持电话禁令减少了研究参与者在开车时使用手持电话的通话。他们还证实了这样一个假设，即禁令促进了开车时打电话的驾驶员从手持电话到免提电话的替代。
结论：这些发现应鼓励其他州颁布全面的手持电话禁令，以改善交通安全。
方法：利用伊利诺伊州2012-2017年交通安全文化指数年度管理部门的数据和一组控制状态。数据被放入差异差异(DID)建模框架中，在干预前后自我报告三种结果的驾驶员比例变化方面，将伊利诺伊州与控制州进行了比较。每个结果的单独模型都是拟合的，以及其他型号适合在开车时用手机通话的驾驶员子集。
结果：在伊利诺伊州，与处于控制状态的驾驶员相比,干预前后驾驶员通过手持电话进行自我报告的概率下降明显更为极端(DID估计值-0.22;95%CI-0.31,-0.13).在开车时打电话的司机中，与对照组相比，伊利诺伊州的那些州在驾驶时使用免提电话通话的可能性增加了更多（DID估计0.13；95％CI0.03，0.23）。
结论：这些结果表明，伊利诺伊州的手持电话禁令减少了研究参与者在开车时使用手持电话的通话。他们还证实了这样一个假设，即禁令促进了开车时打电话的驾驶员从手持电话到免提电话的替代。
结论：这些发现应鼓励其他州颁布全面的手持电话禁令，以改善交通安全。
