Trucks at Work Blog

“What’s clear from surveys, despite some variability in their findings, is that bans on hand-held phoning while driving can have big, long-term effects, but the safety implications still aren’t clear. Many drivers still use their hand-held phones, even where it’s banned, and other drivers simply switch to hands-free phones, which doesn’t help because crash risk is about the same, regardless of phone type.” –Adrian Lund, president, Insurance Institute for Highway Safety

Here’s a conundrum the growing movement to eliminate distracted driving must solve: do laws banning the most frequent forms of driver distraction actually succeed in changing patterns of driver behavior behind the wheel?

The answer, it seems, is decidedly mixed – and not in a good way. The Insurance Institute for Highway Safety (IIHS) researchers recently conducted a new round of observations of driver use of hand-held phones in three jurisdictions where the practice is banned. The findings, along with results of previous studies, reveal a critical divergence – in some jurisdictions, such behavior declines and stays down, while in others, it only initially declines, then starts trending back up.

In the District of Columbia, the proportion of drivers using hand-held phones dropped by about half immediately after a ban on hand0held cell phone use while driving took effect in 2004. Nearly five years later, IIHS said, cell phone use while driving has edged up a little, but the decline is largely holding relative to nearby Virginia and Maryland.

That’s not the case, however, in New York – the first U.S. state to prohibit drivers from using hand-held phones in 2001. Connecticut enacted a ban in 2005. Comparing trends in New York with nearby Connecticut – which enacted a similar ban in 2005 – IIHS researcher’s found cell phone use declined an estimated 76% in Connecticut and 47% in New York, but then use began going back up.

To quantify the long-term effects, researchers observed phone use multiple times during 2001-09 in both the study states and nearby communities without phone bans, to estimate the proportion of drivers expected to be using hand-held phones if the laws hadn’t been enacted. By this measure, then, the laws seem to be a success as hand-held phone use was an estimated 65% lower in Connecticut, 24% lower in New York, and 43% lower in the District of Columbia than would have been expected without the laws.

Yet in Connecticut and New York, cell phone use behind the wheel was higher in spring 2009 among women of all ages compared with men and higher among drivers younger than 25 versus 25-59 year-olds. Only 1% of drivers 60 and older were observed using phones, IIHS said.

What’s more worrisome to Adrian Lund, IIHS’ president, is whether drivers are merely trading one distracting habit for another.

“Banning hand-held phones does reduce their use while driving, but it isn’t known whether such bans also reduce crashes,” Lund noted. “Nor is it known how drivers respond when hand-held phones are banned. This has important implications concerning the laws state legislators are considering [for] crash risk is about the same, whether drivers use hand-held or hands-free phones. So if motorists respond to hand-held bans by switching the type of phone they use, they may not be reducing crash risk. What they’re doing, though, is engaging in a practice that’s harder to curb because laws against it are harder to enforce.”

In a 2006 study, the Virginia Tech Transportation Institute (VTTI) equipped cars with video and sensors to estimate the risk associated with using cell phones while driving. The main finding from that research is an almost 3-fold increase in the odds of crashing or nearly crashing when dialing a hand-held phone. Yet there’s also a 1.3 increase in crash risk merely for talking. However, IIHS noted that this study included only 100 cars and not many crashes occurred during the study period, so the results are inconclusive.

VTTI researchers, however, say the risk associated with text messaging may be much higher, based on a new study of truck drivers. The main finding is a 23-fold increase in the odds of crashing, nearly crashing, or drifting from a travel lane among truckers who texted while they drove. A limitation is that most of the incidents involved lane drift or other driver error, not crashes, and it’s unknown how such incidents relate to actual crashes.

Two other studies that relied on the cell phone records of crash-involved drivers show big increases in crash risk when drivers talk on phones, whether hands-free or hand-held, with the risk of a crash involving injury or property damage is four times as high. Other studies conducted on simulators found that cell phone use while driving not only impairs driving performance, the impairment is similar for hand-held and hands-free phones alike.

“Whether the risk associated with phoning or texting while driving is four-fold or 23-fold or somewhere in between, the fact of the risk is clear: Manual dialing and texting seem especially risky, but talking also involves crash risk – and drivers spend more time talking on phones than dialing,” lund pointed out.

IIHS added that no U.S. state currently bans all drivers from using hands-free phones. Though 21 states and the District of Columbia prohibit beginning drivers from using any type of phone, including hands-free, these laws are hard to enforce, the group noted – pointing to research findings in North Carolina that found teenage drivers didn’t curtail phone use in response to such a ban, in part because they didn’t think the law was being enforced.

That “human behavior” element (and oh how often “human behavior” totally CONFOUNDS all the nice and neat theories scientists and others put forth!) is also complicating efforts to get technology to make a difference.

IIHS said one approach to preventing cell phone use of any sort behind the wheel would be to use “Blocking devices” to prevent phone use in moving vehicles. But one problem is that such devices would block phoning by passengers as well as drivers. To get around this, some systems include a passenger mode, IHHS said, but it’s unclear whether drivers can be prevented from activating it to circumvent the whole purpose of the devices. On top of that, cell phone “blockers” of any sort for vehicles aren’t yet in widespread use, and their effects aren’t known.

All of this lays a big layer of complications atop efforts to reduce distracted driving; not unsolvable ones, mind you, but ones that require above all permanent changes in permanent behavior – behavior that many drivers, everyday motorists as well as truckers, feel is a benefit to them when behind the wheel. That will be a very tough nut to crack.