Menus Subscribe Search

Follow us

Quick Studies


(Photo: 9575673@N08/Flickr)

Why Didn’t California’s Handheld Phone Ban Reduce Motor Accidents?

• July 18, 2014 • 10:31 AM

(Photo: 9575673@N08/Flickr)

Are handheld cell phones as dangerous as they have been made out to be?

This month marks the six-year anniversary of California’s ban on the use of handheld cell phones by motorists—a regulation that has now spread to 13 states. So, happy birthday, ban. Your present is a fresh scientific debate over the validity of your very existence.

The body of evidence suggests that driving while distracted by talking on a handheld phone is dangerous. An oft-cited study from 1997 found that using a cell phone more than quadruples a driver’s chance of having an accident. California commissioned a study by the University of California-Berkeley in 2012 that concluded that deaths blamed on the use of handheld phones by drivers were slashed by nearly half during the two years following the ban (compared with two years before it).

But something isn’t adding up.

“It’s possible that people who continued to use their cell phones were people who were more inclined to get into accidents anyway.”

Researchers from the University of Colorado and RAND Corporation teamed up with a statistics expert from the Colorado School of Mines to crunch numbers from the large and comprehensive databases of daily accidents on freeways throughout 2008 in nine of California’s traffic districts. After controlling for covariates, such as rainfall and holidays, the accident rate during the six months that preceded the ban looked awfully similar to the rate during the six months that followed.

“Across various specifications, we find no evidence of a reduction in accidents state-wide due to the ban,” the researchers concluded in a paper published recently in Transportation Research Part A.

The authors of the paper say they are “agnostic” about the cause of their surprising finding.

“It’s possible that people who continued to use their cell phones were people who were more inclined to get into accidents anyway,” says Daniel Kaffine, an associate professor in University of Colorado-Boulder’s economics department and one of the three authors of the new paper. “Riskier drivers might have been the ones who said, ‘To hell with it; I’m going to use my phone anyway.'”

Kaffine pointed to research published in 2007 that found that drivers who reported using handheld phones while behind the wheel were more likely to crash than other drivers—even when they weren’t yammering away on the phone.

“The other side of the coin is just that maybe it’s the case that cell phones aren’t as risky as some of these previous studies have suggested,” Kaffine says.

The California Office of Traffic Safety welcomed the study about as warmly as someone receiving a speeding ticket. The office’s spokesman, Chris Cochran, argued that the single year’s worth of data used by the researchers was insufficient.

“The Statewide Integrated Traffic Records System shows figures for 22 primary collision factors alone, not to mention all the contributing factors,” Cochran says. “They vary up and down from year to year, but, overall, each has been trending down for the last decade. By saying that since the overall figures did not drop, then laws against one causal factor, out of the dozens possible, must not be working is illogical.”

John Upton
John Upton is a science journalist with an ecology background. He has written recently for VICE, Slate, Nautilus, Modern Farmer, Grist, and Audubon magazine. He blogs at Wonk on the Wildlife. Upton's favorite eukaryotes are fungi, but he won't fault you for being human. Follow him on Twitter @johnupton.

More From John Upton

A weekly roundup of the best of Pacific Standard and, delivered straight to your inbox.

Recent Posts

October 31 • 12:00 PM

In the Picture: SNAP Food Benefits, Birthday Cake, and Walmart

In every issue, we fix our gaze on an everyday photograph and chase down facts about details in the frame.

October 31 • 10:15 AM

Levels of Depression Could Be Evaluated Through Measurements of Acoustic Speech

Engineers find tell-tale signs in speech patterns of the depressed.

October 31 • 8:00 AM

Who Wants a Cute Congressman?

You probably do—even if you won’t admit it. In politics, looks aren’t everything, but they’re definitely something.

October 31 • 7:00 AM

Why Scientists Make Promises They Can’t Keep

A research proposal that is totally upfront about the uncertainty of the scientific process and its potential benefits might never pass governmental muster.

October 31 • 6:12 AM

The Psychology of a Horror Movie Fan

Scientists have tried to figure out the appeal of axe murderers and creepy dolls, but it mostly remains a spooky mystery.

October 31 • 4:00 AM

The Power of Third Person Plural on Support for Public Policies

Researchers find citizens react differently to policy proposals when they’re framed as impacting “people,” as opposed to “you.”

October 30 • 4:00 PM

I Should Have Told My High School Students About My Struggle With Drinking

As a teacher, my students confided in me about many harrowing aspects of their lives. I never crossed the line and shared my biggest problem with them—but now I wish I had.

October 30 • 2:00 PM

How Dark Money Got a Mining Company Everything It Wanted

An accidentally released court filing reveals how one company secretly gave money to a non-profit that helped get favorable mining legislation passed.

October 30 • 12:00 PM

The Halloween Industrial Complex

The scariest thing about Halloween might be just how seriously we take it. For this week’s holiday, Americans of all ages will spend more than $5 billion on disposable costumes and bite-size candy.

October 30 • 10:00 AM

Sky’s the Limit: The Case for Selling Air Rights

Lower taxes and debt, increased revenue for the city, and a much better use of space in already dense environments: Selling air rights and encouraging upward growth seem like no-brainers, but NIMBY resistance and philosophical barriers remain.

October 30 • 9:00 AM

Cycles of Fear and Bias in the Criminal Justice System

Exploring the psychological roots of racial disparity in U.S. prisons.

October 30 • 8:00 AM

How Do You Make a Living, Email Newsletter Writer?

Noah Davis talks to Wait But Why writer Tim Urban about the newsletter concept, the research process, and escaping “money-flushing toilet” status.

October 30 • 6:00 AM

Dreamers of the Carbon-Free Dream

Can California go full-renewable?

October 30 • 5:08 AM

We’re Not So Great at Rejecting Each Other

And it’s probably something we should work on.

October 30 • 4:00 AM

He’s Definitely a Liberal—Just Check Out His Brain Scan

New research finds political ideology can be easily determined by examining how one’s brain reacts to disgusting images.

October 29 • 4:00 PM

Should We Prosecute Climate Change Protesters Who Break the Law?

A conversation with Bristol County, Massachusetts, District Attorney Sam Sutter, who dropped steep charges against two climate change protesters.

October 29 • 2:23 PM

Innovation Geography: The Beginning of the End for Silicon Valley

Will a lack of affordable housing hinder the growth of creative start-ups?

October 29 • 2:00 PM

Trapped in the Tobacco Debt Trap

A refinance of Niagara County, New York’s tobacco bonds was good news—but for investors, not taxpayers.

October 29 • 12:00 PM

Purity and Self-Mutilation in Thailand

During the nine-day Phuket Vegetarian Festival, a group of chosen ones known as the mah song torture themselves in order to redirect bad luck and misfortune away from their communities and ensure a year of prosperity.

October 29 • 10:00 AM

Can Proposition 47 Solve California’s Problem With Mass Incarceration?

Reducing penalties for low-level felonies could be the next step in rolling back draconian sentencing laws and addressing the criminal justice system’s long legacy of racism.

October 29 • 9:00 AM

Chronic Fatigue Syndrome and the Brain

Neuroscientists find less—but potentially stronger—white matter in the brains of patients with CFS.

October 29 • 8:00 AM

America’s Bathrooms Are a Total Failure

No matter which American bathroom is crowned in this year’s America’s Best Restroom contest, it will still have a host of terrible flaws.

October 29 • 6:00 AM

Tell Us What You Really Think

In politics, are we always just looking out for No. 1?

Follow us

Levels of Depression Could Be Evaluated Through Measurements of Acoustic Speech

Engineers find tell-tale signs in speech patterns of the depressed.

We’re Not So Great at Rejecting Each Other

And it's probably something we should work on.

Chronic Fatigue Syndrome and the Brain

Neuroscientists find less—but potentially stronger—white matter in the brains of patients with CFS.

Incumbents, Pray for Rain

Come next Tuesday, rain could push voters toward safer, more predictable candidates.

Could Economics Benefit From Computer Science Thinking?

Computational complexity could offer new insight into old ideas in biology and, yes, even the dismal science.

The Big One

One town, Champlain, New York, was the source of nearly half the scams targeting small businesses in the United States last year. November/December 2014

Copyright © 2014 by Pacific Standard and The Miller-McCune Center for Research, Media, and Public Policy. All Rights Reserved.