It’s well known that cellphone use in the car distracts drivers’ attention from the road. This problem, known as distracted driving, remains a top cause of traffic fatalities each year. Responding to this problem, Minnesota’s hands-free law went into effect this month; it bans the use of hand-held phones while driving. Proponents argue the law will create safer roads by reducing distracted driving.
However, there are reasons to be skeptical it’ll work. To understand why, we need to look carefully at statistics on hands-free laws to see if they reduce distracted driving. Likewise, we need to look at controlled experiments that study whether hands-free devices make driving safer.
Let’s start with statistics. As a case in point, consider the following stat reported on the Office of Traffic Safety (OTS) site: In 12 of 15 states with hands-free laws, traffic fatalities have decreased by an average of 15 percent.
Curious to verify the source of this stat, I contacted OTS. It referred me to a report, which showed an average decrease of traffic fatalities in states after they passed hands-free laws. Nevertheless, the report raised a couple of questions.
First, I wanted to make sure the decrease in traffic fatalities was based on rates, not counts. This distinction matters, because if the number of fatalities decreased, but the amount of driving went down too, the overall rate of fatalities may not have decreased. (Note: The amount of driving is usually measured by Vehicle Miles Traveled, or VMT, a measurement of total miles driven within a geographic area for some period of time.)
Did report pinpoint the cause?
Second, if the rates of traffic fatalities did decrease, I wanted to know if the report pinpointed the cause. Statistically speaking, when traffic fatalities fall in states after they pass hands-free laws, we can’t assume it’s because distracted driving went down. After all, traffic fatalities may fall because other causes of traffic fatalities went down, such as drunk driving, drowsy driving, speeding, etc.
When I asked OTS these questions, it referred me to the MN Safety Council, which courteously responded to my inquiry. I learned the aforementioned stat was based on National Highway Traffic Safety Administration (NHTSA) data cited in a 2017 Georgia report (“House Study Committee on Distracted Driving”), which indeed showed decreased rates in fatalities (relative to VMT). That was the good news.
The bad news? The report couldn’t pinpoint what caused this decrease. In other words, assuming the rates of traffic fatalities did fall in some states after they passed hands-free laws, it’s unclear if the laws caused that decrease by reducing distracted driving. As mentioned, traffic fatalities have a number of causes, and studies that try to control for these causes — for example, research on insurance claim rates, hand-held phone bans, and automobile-accident data — have shown no conclusive evidence hands-free laws reduce distracted driving-related deaths, crashes, or accidents.
What does science have to say?
Hence, a question arises: Does hands-free cellphone use make driving safer? To answer it, we need to look at controlled experiments. So, what does the science have to say about using hands-free devices behind the wheel?
To date, there’s a consensus that using hands-free devices is as dangerous as using hand-held phones. Using driving simulation tests, scientists have discovered the accident rates are the same for drivers whether they use hand-held phones or hands-free devices. Why? Because the root cause of distracted driving isn’t physical interference from the phone; it’s mental interference from the phone conversation.
As I’ve written before, cellphones interfere with driving performance — and make drivers prone to causing accidents — by diverting attention from one task (the driving) to another (the phone conversation). Consequently, if drivers in states with hand-held phone bans just switch to hands-free devices, their risk of being in a car crash remains unchanged. In fact, the risk is comparable to drunk driving.
To be fair, it’s possible to suggest Minnesota’s hands-free law might reduce distracted driving by accident (no pun intended), because not everyone owns a headset. By this line of reasoning, drivers without headsets would refrain from using phones in the car. Yet, it’s also possible those drivers will place phones in their laps and look down behind the wheel.
Additionally, it’s possible to suggest the hands-free law might improve road safety by raising public awareness of distracted driving. Even so, initial improvements in road safety could be followed by backsliding, especially if we don’t get to the root cause of distracted driving. As the MN Safety Council reports, hands free doesn’t mean distraction free.
Therefore, the safest thing everyone can do is not dial and drive. Furthermore, our representatives should pass legislation banning most cellphone use in the car, including headsets (obviously, with exceptions like emergency calls or GPS). Granted, the trade-off would entail giving up a slice of technological convenience. But your life and the lives of your loved ones and neighbors, I hope you agree, ought to be a higher priority.
Christopher Cocchiarella is a training & development specialist at the State of Minnesota and a technology education advocate on the side. He can be reached on his website, mindfultechnics.com.
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