Cellphones may not raise car crash risk

CARNEGIE MELLON (US) — Talking on a cellphone while driving does not increase the likelihood of a car accident, according to a new analysis.

Published in the American Economic Journal: Economic Policy, the study uses data from a major cellphone provider and accident reports to contradict previous findings that connected cellphone use to increased crash risk.

Such findings include the influential 1997 paper in the New England Journal of Medicine, which concluded that cellphone use by drivers increased crash risk by a factor of 4.3—effectively equating its danger to that of illicit levels of alcohol.

The findings also raise doubts about the traditional cost-benefit analyses used by states that have, or are, implementing cellphone-driving bans as a way to promote safety.

“Using a cellphone while driving may be distracting, but it does not lead to higher crash risk in the setting we examined,” says Saurabh Bhargava, assistant professor of social and decision sciences at Carnegie Mellon University.

“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.”

Do cellphone bans work?

For the study, Bhargava and the London School of Economics and Political Science’s Vikram S. Pathania examined calling and crash data from 2002 to 2005, a period when most cellphone carriers offered pricing plans with free calls on weekdays after 9 p.m. Identifying drivers as those whose cellphone calls were routed through multiple cellular towers, they first showed that drivers increased call volume by more than 7 percent at 9 p.m.

They then compared 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 the increased cellphone use by drivers at 9 p.m. had no corresponding effect on crash rates.

Additionally, the researchers analyzed the effects of legislation banning cellphone use, enacted in several states, and similarly found that the legislation had no effect on the crash rate.

“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 says. “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.”

Pathania, a fellow in the London School of Economics Managerial Economics and Strategy group, adds a cautionary note. “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.”

Source: Carnegie Mellon University

chat6 Comments


  1. Nick Dalfonso

    Every single statement in this study is the same as verbal diaherra.
    Let’s see, we want to sell more plans, even if we kill a few more people on the way , so lets prove that using your minutes while driving doesn’t require any mental effort..

  2. Mike

    What terrible “science”, if you can even call it that. To rely on the fact that people “increased call volume by more than 7 percent at 9 p.m” as your base for the entire study is stupid. Are these callers even in a car at the time? I’m going to say probably not, but you have no way of knowing. Most people I know using their “free minutes” are at home chatting up friends, and those people doing “business” while driving are doing it during the day.

    But using this kind of science: more people tend to sleep at night, and accidents decrease as night. I guess sleeping prevents accidents—sooo I’m going to start sleeping behind the wheel as much as possible now!

    Pathetic how people doing these studies have no clue about actual “scientific methods”, and let’s not even try to describe correlation versus “cause and effect”. None of the statistics that media reports ever get that one right.

    How about this: the “laws” created to reduce cell phone usage are pathetic and ineffective. Where I live it’s a $1000 fine for tossing a piece of trash out of your car, but only $25 if you’re caught using a cell phone. Does the fine deter me (or anyone else on the road)–nope.

  3. Pho Geez

    Easy investigation. Pull all usage of cellphones from all carriers at rush hour times. Cross reference that with crash data. This is similiar to DUI Enforcement patrols which never happen after major sporting events at arenas. Staduim seats 70,000 + alcohol tab (which is on the books) + crash data after games – no DUI patrol =. And why do we pay insurance again in a FREE Society? P.S. yes it is sad anyone dies while someone is on cellphones and someone is drunk. But the politicking + data don’t match the statistics of either case.

  4. Pho Geez

    Why not require people to be trained on how to use cellphones while driving. For instance folks should put the cellphone down when approach intersections or changing lanes. Public service announcement. etc…

  5. Dmitry

    What a waste of a study, time and money. Most likely sponsored by phone companies. Use of cellphones while driving is dangerous. Not every driver texts or tweets or looks at their phone while driving, but there are many that do.

  6. Personal Injury Solicitors Guilford

    I’m not sure that I agree with a single sentence in this study. If you’re having a conversation on the phone, it’s obvious that your full attention isn’t going to be on the road – this is when accidents happen. I also struggle to see why it’s an issue in the first place; what conversation is so important that it can’t wait until you’ve finished your journey or pulled over safely?

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