Does Talking on the Phone and Driving Really Put You More at Risk for a Crash?

Though many health experts caution against the dangers of driving and talking on your cell phone, researchers from Carnegie Mellon University and the London School of Economics and Political Science actually suggest that this may not increase a driver's crash risk.

Using a cellphone while driving may be distracting, but it does not lead to higher crash risk in the setting we examined," said Saurabh Bhargava, assistant professor of social and decision sciences in CMU's Dietrich College of Humanities and Social Sciences, via a press release. "While our findings may strike many as counterintuitive, our results are precise enough to statistically call into question the effects typically found in the academic literature. Our study differs from most prior work in that it leverages a naturally occurring experiment in a real-world context."

The study examined calling and crash data from 2002 and 2005, a period when most cellphone carriers offered pricing plans with free calls on weekdays just after 9 p.m. They then identified drivers whose cellphone calls were routed through multiple cellular towers, first showing signs that the drivers call volume was more than 7 percent at 9 p.m. This was then compared to the relative crash rate before and after 9 p.m. using data on approximately 8 million crashes across nine states and all fatal crashes across the nation. They found that increased cellphone use by drivers at 9 p.m. had no corresponding effect on crash rates.

Upon analyzing the effects of banning cell phone use in different states, they also found that certain legislations had no effect on crash rate, either. 

"One thought is that drivers may compensate for the distraction of cellphone use by selectively deciding when to make a call or consciously driving more carefully during a call," Bhargava said, via the release. "This is one of a few explanations that could explain why laboratory studies have shown different results. The implications for policymakers considering bans depend on what is actually driving this lack of an effect. For example, if drivers do compensate for distraction, then penalizing cellphone use as a secondary rather than a primary offense could make sense. In the least, this study and others like it, suggest we should revisit the presumption that talking on a cellphone while driving is as dangerous as widely perceived."

He concluded the following, noting that: "Our study focused solely on talking on one's cellphone. We did not, for example, analyze the effects of texting or Internet browsing, which has become much more popular in recent years. It is certainly possible that these activities pose a real hazard."

More information regarding the study can be found in American Economic Journal: Economic Policy.