Laws banning cell phone use, including texting, while driving apparently don't result in actually reducing vehicle crashes, according to a new study that was immediately criticised by the US Department of Transportation as "irresponsible."
The study by the Highway Loss Data Institute, released last week, compared insurance claims for crash damage in four jurisdictions before and after cell phone bans. There were "no reductions in crashes" after the bans took effect compared with nearby jurisdictions that had no such restrictions. HLDI is an affiliate of the Insurance Institute for Highway Safety. The complete 5-page report is online. Transportation Secretary Ray LaHood just recently proclaimed rules forbidding commercial truck and bus drivers from texting while driving, with fines, if caught, of up to US$2,750 and jail time if there's an accident caused by a texting driver. LaHood has said he would ban all texting while driving if he could, according to the Wall Street Journal story on the HLDI report. The basis of the ban lies in a number of studies that show text messaging with cell phones is an especially distracting activity, endangering drivers, passengers and those around them. Network World editor Paul McNamara wrote recently in his BuzzBlog, in favour of texting bans, "The data has been piling up for years, too, witness this study that says truck drivers who text from the road are 23 times more likely to have an accident....Those penalties — and jail time if an accident occurs — are more than justified by the danger these drivers are creating; danger to their passengers, other drivers, and themselves." But the HLDI report concludes that cell phone and phone texting bans are not reducing crashes. "The laws aren't reducing crashes, even though we know that such laws have reduced hand-held phone use, and several studies have established that phoning while driving increases crash risk," says Adrian Lund, president of both the Insurance Institute for Highway Safety and HLDI, a statement quoted in the HLDI press release. Also from the press release: "The HLDI database doesn't identify drivers using cellphones when their crashes occur. However, reductions in observed phone use following bans are so substantial and estimated effects of phone use on crash risk are so large that reductions in aggregate crashes would be expected. In New York the HLDI researchers did find a decrease in collision claim frequencies, relative to comparison states, but this decreasing trend began well before the state's ban on hand-held phoning while driving and actually paused briefly when the ban took effect. Trends in the District of Columbia, Connecticut, and California didn't change."
So cell phones bans cut highly risky behavior by reducing the incidence of phoning while driving, but they don't seem to result in fewer crashes.
"This finding doesn't auger well for any safety payoff from all the new laws that ban phone use and texting while driving," Lund says.
The report offered some speculation on why the number of crashes isn't dropping. One possible reason is that drivers switch to hands-free phones, which currently aren't banned in any state. In other words, they're still talking, if not texting, on their phones, and therefore presumably still crashing at the same frequency. "In this case crashes wouldn't go down [i.e., decrease] because the risk is about the same, regardless of whether the phones are hand-held or hands-free," according to the press release summary of the report's findings.
"Twenty-one states and the District of Columbia do prohibit beginning drivers from using any type of phone, including hands-free, but such laws are difficult to enforce. This was the finding in North Carolina, where teenage drivers didn't curtail phone use in response to a ban, in part because they didn't think the law was being enforced."
The Institute is gathering additional data to explore these mismatches in more detail.
But the DOT isn't waiting for more data. In a statement on Friday, the agency criticised the conclusions, according to the Wall Street Journal story linked to above: "...it is irresponsible to suggest that laws banning cell phone use while driving have zero effect on the number of crashes on our nation's roadways. A University of Utah study [presumably this one from June 2006] shows that using a cell phone while driving can be just as dangerous and deadly as driving drunk. We know that by enacting and enforcing tough laws, states have reduced the number of crashes leading to injuries and fatalities." But a study that shows only that phoning while driving is dangerous, even as dangerous as driving drunk, can't be used prove that banning the behavior reduces crashes. Drunk driving, for example, remains a problem, despite tough drunk-driving laws: in 2008, vehicle fatalities that were alcohol-related were 32 percent of all vehicle deaths, unchanged from 2007, according to the National Highway Traffic Safety Administration. The DOT's criticism, in effect, denounces the study by appealing to what everyone "knows" and by refusing to consider how or even whether other data may challenge those assumptions.