Research shows cellphone use may not cause more car crashes

August 8, 2013, Carnegie Mellon University

For almost 20 years, it has been a wide-held belief that talking on a cellphone while driving is dangerous and leads to more accidents. However, new research from Carnegie Mellon University and the London School of Economics and Political Science suggests that talking on a cellphone while driving does not increase crash risk.

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 . 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," said Saurabh Bhargava, assistant professor of social and decision sciences in CMU's Dietrich College of Humanities and Social Sciences. "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."

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 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 .

"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. "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, added a cautionary note. "Our study focused solely on talking on one's . 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."

Explore further: Fatal crashes involving cellphone use may be under-reported

More information: Driving Under the (Cellular) Influence (with Vikram Pathania), American Economic Journal: Economic Policy, Vol. 5, No. 3, pp. 92-125, 2013. … Pathania2013_AEJ.pdf

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1.4 / 5 (12) Aug 08, 2013
Which only demonstrates the fraud that permeates "science". In fact, the "study" that concluded cell phone use "caused" accidents was commissioned by a state legislature that wanted an excuse to impose more fines and give insurance carrier crooks a way to weasel out of coverage. The "researchers" "defined' a cell phone as "causing" a crash if it was used within ten minutes of the accident. So you could take a call at a restaurant, get in your car, drive out and have the drugged out kid of a politico plow into you and you would be blamed! The fact is "science" is nothing more than a figurehead, anymore. "Scientists" play gin rummy behind "laboratory" doors, then "publish" pieces of paper with numbers on them, make corporate friendly claims and the gullible believe them.
4.3 / 5 (6) Aug 08, 2013
It's not talking, it's dialing and texting that take your eyes and brain off the road. Talking to a phone is no more distracting than the radio or a passenger.
3.9 / 5 (7) Aug 08, 2013
I immediately see one major flaw in this study. How many accidents do cell phone users cause to others and they don't even realize it? Nearly every single time I drive across my city I have to swerve to avoid someone moving into my lane without looking. I always look to see if they are on a cell phone. Only on a rare occasion are they NOT holding a phone to their head.
1 / 5 (3) Aug 08, 2013
Nonsense. I was nearly killed when the driver of the car entered in a phone number to dial instead of looking at the freeway. The car head straight toward an unprotected concrete road divider that could have split the machine in two with four passengers aboard

A Mexican train conductor was sexting his underage boyfriends when he colluded with another train, causing the engine to move backward into a passenger compartment killing about sixty in Chatsworth
5 / 5 (4) Aug 08, 2013
@kochevnik the article stated that texting wasn't factored in. But I agree that the term "cellphone use" is so broad that it's silly to say that cellphone use *doesn't* increase the risk of crashes when it encompasses dialing and texting which require you to take your eyes off the road.

Perhaps it's better to analyze how much time someones eyes are taken off the road, whether it's texting, putting on make up, or changing to a different radio station.
3.7 / 5 (6) Aug 08, 2013
Doing anything that diverts attention whilst driving increases the chances of having an accident on the roads.
not rated yet Aug 08, 2013
2010: The National Safety Council announced today that it estimates at least 28% of all traffic crashes – or at least 1.6 million crashes each year – involve drivers using cell phones and texting. NSC estimates that 1.4 million crashes each year involve drivers using cell phones and a minimum of 200,000 additional crashes each year involve drivers who are texting.

You don't have to be a scientist or conduct any study at all to take note that 25% of people on the road aren't on a cellphone. So, what gives.. Statistics, or this research? You're clearly much more likely to get in an accident on a cellphone, based on NSC numbers.
not rated yet Aug 08, 2013
Of course cell phone usage after 9pm would go up for everybody (including those who are on the road). That does not mean that DRIVERS are calling. It could be other people in the car that use cell phones. In this case it of course would not affect any crash statistics.
if however it were DRIVERS using cell phones - then it WOULD affect it.
3 / 5 (2) Aug 08, 2013
I'm sorry, but this is totally irresponsible research. There are much better studies with much more direct evidence showing that cell phone use (talking or texting or checking facebook or whatever homicidal drivers do with their phones while trying to kill as many innocent people as possible...ok, exaggeration but that's what I think of them). They used correlation to infer causation here. They did not track individual phone users and see if they were or weren't in accidents. They just said that after 9pm, cell phone use in cars (they can't even identify the cell phone users as the driver because it could have been a passenger) goes up, but accident rate doesn't go up. Guess what, there are fewer cars on the road too. Way too many ways for the real effect of cell phone use to be subtly masked in this study.
5 / 5 (1) Aug 09, 2013
They can't even remotely prove that cell phone usage in cars goes up after 9. People calling after 9 are the people at home that wait for 9 o'clock so they can call their family/friends/whatever for free. Personally I don't think the 9 o'clock thing affect drivers in cars as much. Really a dumb study.
3 / 5 (2) Aug 09, 2013
Paid for by whom? We all understand that people talking over wireless connections is the 'lifeblood' of industry. We also know that it is very easy to spot someone deep in conversation on a cell phone while driving the fast lane on the freeway/feeway/highway.

5 / 5 (1) Aug 09, 2013
It's not talking, it's dialing and texting that take your eyes and brain off the road. Talking to a phone is no more distracting than the radio or a passenger.

I disagree. Many minds cannot do more than one thing a a time. Multitaskers, NOT!

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