There are no reliable estimates of the number of crashes caused by distracted drivers. Most of what we know about cellphones and crash risk comes from naturalistic studies. Such studies have consistently linked texting or otherwise manipulating a phone to increased risk. There is mixed evidence about whether talking on a cellphone increases crash risk.
Based on national police-reported data on fatal crashes in the United States during 2019, 3,142 people died in motor vehicle crashes in which distraction was deemed a contributing factor. That is nearly 9 percent of all crash deaths. Of that number, 422, or 1 percent of people killed on the roads, died in crashes involving cellphone use.
Statistics based on police-reported crash data almost certainly underestimate the role of distraction in fatal crashes. Police crash reports aren't a reliable way to count cellphone-related collisions because drivers often don't volunteer that they were on the phone and there is usually a lack of other evidence to determine drivers' phone use.
Data from over 3,000 drivers who were continuously monitored for up to 3 years during 2010-13 have been used for several studies of the effect of cellphone conversations. Three of these (Dingus et al., 2016; Kidd & McCartt, 2015; Guo et al, 2016), including one by IIHS researchers, found that talking on a cellphone significantly increased crash risk compared with periods when drivers were not visibly distracted, although the risk was limited to drivers 16-29 in the third. In contrast, another analysis of the same data found that talking on a hand-held cellphone did not significantly increase crash risk (Owens et al., 2018). This finding is consistent with an earlier IIHS study of cellphone use by 105 drivers during a one-year period (Farmer et al., 2015).
>>Continue reading ...
The evidence is clearer when it comes to texting or manipulating a cellphone. The three analyses of data from the naturalistic study of over 3,000 drivers indicated that crash risk was 2-6 times greater when drivers were manipulating a cellphone compared with when they were not distracted (Dingus et al., 2016; Kidd & McCartt, 2015; Owens et al., 2018). When looked at by age group, there was a significant increase in crash risk for drivers under 30 years old and drivers over 64 (Guo et al., 2016).
Nearly all experimental studies using driving simulators or instrumented vehicles reported that some measures of driver performance were affected by the cognitive distractions associated with cellphone tasks (McCartt et al., 2006). Statistical analyses aggregating the results of multiple studies reported significant delays in drivers' reaction time but little or no effect of cellphone conversations on lane keeping, speed or following distance (Caird et al., 2008; Horrey & Wickens, 2006).
An analysis aggregating the results of 28 experimental studies using driving simulators or instrumented vehicles reported that typing or reading text messages significantly slowed reaction time, increased lane deviations and increased the length of time drivers looked away from the roadway (Caird et al., 2014).
Cellphone use also affects how drivers scan and process information from the roadway. Drivers generally take their eyes off the roadway to dial or manipulate a hand-held phone. In contrast, drivers engaged in cellphone conversations and other forms of cognitive distraction tend to concentrate their gaze toward the center of the roadway (Recarte & Nunes, 2000; Recarte & Nunes, 2003; Reimer et al., 2012), but their attention still may be diverted from driving and this may make it difficult for drivers to process what they are looking at (Strayer et al., 2003).
Researchers have found that brain activity associated with visual processing and attention is suppressed when drivers are cognitively distracted (Bowyer et al., 2009: Strayer et al., 2006; Just et al., 2008). Consequently, cognitive distractions can lead to so-called "inattention blindness" in which drivers fail to comprehend or process information from objects in the roadway even when they are looking at them (Strayer et al., 2003).
Reprinted with permission from the Insurance Institute for Highway Safety. Please visit here for the original article.
»Show less …