Cellphone crash risk may be overplayed

2011-12-13 14:30


  • Accidents
    A resource for all Health and Safety professionals, particularly those who have responsibility for... Now R521.00
    buy now

Detroit - The increased risk of having a car crash attributed to people using their cellphones while driving may have been overestimated in some past studies, a US analysis said.

So-called "distracted driving" has become a big public health issue in recent years, and the majority of US states now ban texting behind the wheel. A handful prohibit drivers from using handheld cellphones at all.

But studies have reached different conclusions about how much of an added crash risk there is, and a recent analysis by researchers at the Wayne State University School of Medicine in Detroit found that two influential studies may have overestimated the risk.

Lead author Richard Young wrote in the journal Epidemiology that the method of two studies on the issue - one 1997 study in Canada, and another from Australia in 2005, which said that cellphone use while driving raised the crash risk four-fold - may have posed problems.

Control window

The studies recruited people who had been in a crash, and then used their billing records to compare their cellphone use during the time of the crash with their cell use during the same time period the week before, a so-called "control window".

"Earlier ... studies likely overestimated the relative risk for cellphone conversations while driving by implicitly assuming that driving during a control window was full-time when it may have been only part-time," he wrote.

Such "part-time" driving would necessarily cut the odds of having a crash, and possibly reduce people's cellphone use, during the control window - and make it seem as if cellphone use is a bigger crash risk.

The two studies asked people if they had been driving during the control window, but they did not account for part-time driving.

Young and his team used GPS data to track day-to-day driving consistency for 439 drivers over 100 days. The days were grouped into pairs: day one was akin to the "control" days used in the earlier studies, and day two the equivalent of the "crash" day.

Statistically insignificant

Overall, there was little consistency between the two days when it came to driving time. When he looked at all control windows where a person did some driving, the total amount of time on the road was about one-fourth of what it was during a "crash" day.

If that information was applied to the two earlier studies, Young estimates, the crash risk tied to cellphone use would have been statistically insignificant - and may help explain why some earlier studies have not linked cellphone use to an increased crash risk.

Fernando Wilson, an assistant professor at the University of North Texas Health Science Centre who was not involved in the analysis, said that the two earlier studies may well have overstated the risk.

But a number of other studies designed in different ways suggest that cellphone use - and especially texting - is indeed hazardous on the road, he added.

In his own study published last year, Wilson looked at information from a government database tracking deaths on US public roads. After declining between 1999 and 2005, deaths blamed on distracted driving rose 28% between 2005 and 2008.

"In wider policy, I don't think this study is going to change the conversation about distracted driving. Most of the conventional thinking is that we need to do something to reduce it," he told Reuters Health.

Read more on:    us  |  accidents  |  mobile

Read News24’s Comments Policy

24.com publishes all comments posted on articles provided that they adhere to our Comments Policy. Should you wish to report a comment for editorial review, please do so by clicking the 'Report Comment' button to the right of each comment.

Comment on this story
Add your comment
Comment 0 characters remaining

Inside News24


Zuma: Pray for peaceful polls

President Jacob Zuma has asked members of the Universal Church of the Kingdom of God to pray for peaceful elections on 7 May.


Latest elections multimedia

Why Jack Parow wants you to vote on 7 May
The ad the SABC doesn't want to air
Elections 2014 in one cartoon
This year's election posters
  • Saturday Hout Bay - 07:06 AM
    Road name: Chapmans Peak Drive
    ROAD CLOSED until 1400
  • Saturday Cape Town - 07:00 AM
    Road name: Rhodes Drive
    ROAD CLOSED between Constantia Nek and the M3 Highway until 1300
More traffic reports...

Jobs in Cape Town [change area]

Property [change area]

Travel - Look, Book, Go!

Escape winter, head to Mauritius

Escape winter by spending 7 nights in Mauritius' tropical bliss from R13 215 per person sharing. Includes return flights, airport transfers and accommodation. Book now!

Kalahari.com - shop online today

Get many eggs in one basket!

Gaming bundles: 2 Super Hits games for R99, 3 Disney games for R99 and more + exclusive accessory bundles only available on kalahari.com. While stocks last. Shop now!

25% off bestselling books!

The Real Meal Revolution by Tim Noakes, Jeffrey Archer’s Be Careful What You Wish for, Man’s Search for Meaning by Victor E. Frank and many more titles. Shop now!

Up to 25% off electronics

Buy top electronics and save up to 25%. Such as kalahari.com’s 1# selling product the gobii eReader, Patriot X Porter flash drive, Asus Nexus 7” 3G tablet, Samsung Galaxy SIII, Lenovo G580 Notebook and many more. Shop now!

DStv HD PVR Decoder now R949

The DStv HD PVR Decoder has further revolutionised the television experience with lifelike viewing, sharper images, more vibrant colours and precision picture quality. Now R949, save R550. Offer valid while stocks last. Shop now!

Up to 30% off appliances & homeware

Save up to 30% on appliances and homeware this Easter! Offer valid while stocks last. Shop now.

OLX Free Classifieds [change area]

Samsung Galaxy s4

Mobile, Cell Phones in South Africa, Western Cape, Cape Town. Date October 24

Best bargain in big bay

Real Estate, Houses - Apartments for Sale in South Africa, Western Cape, Cape Town. Date October 25

VW Golf 6, 1.6 Trendline (Excellent condition)

Vehicles, Cars in South Africa, Western Cape, Cape Town. Date October 25

Nokia C3

The Nokia C3 Features a 2+ Megapixel Camera, A2DP, Bluetooth,...

From R1175.00

I'm shopping for:


Self-indulgence may be strong today. You may want to enjoy yourself to the fullest and share it with those that make you feel...read more

There are new stories on the homepage. Click here to see them.


Create Profile

Creating your profile will enable you to submit photos and stories to get published on News24.

Please provide a username for your profile page:

This username must be unique, cannot be edited and will be used in the URL to your profile page across the entire 24.com network.


Location Settings

News24 allows you to edit the display of certain components based on a location. If you wish to personalise the page based on your preferences, please select a location for each component and click "Submit" in order for the changes to take affect.

Facebook Sign-In

Hi News addict,

Join the News24 Community to be involved in breaking the news.

Log in with Facebook to comment and personalise news, weather and listings.