Arlington, Virginia – Bans on the use of hand-held cell phones while driving are not reducing the number of crashes, according to a new study by the Highway Loss Data Institute (HLDI), an affiliate of the U.S. Insurance Institute for Highway Safety (IIHS).

Comparing insurance claims for crash damage in four U.S. jurisdictions before and after such bans, the researchers found steady claim rates compared with nearby jurisdictions without such bans.

HLDI researchers calculated monthly collision claims per 100 insured vehicle years for vehicles up to three years old during the months immediately before and after hand-held phone use was banned while driving in New York (November 2001), the District of Columbia (July 2004), Connecticut (October 2005), and California (July 2008). Comparable data were collected for nearby jurisdictions without such bans. The method controlled for possible changes in collision claim rates unrelated to the bans, such as changes in the number of miles driven due to the economy, or seasonable changes in driving patterns.

Month-to-month fluctuations in rates of collision claims in jurisdictions with bans did not change from before to after the laws were enacted. The patterns also didn’t change in comparison with trends in jurisdictions without cell phone bans.

“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,” said Adrian Lund, president of IIHS and HLDI.

A previous IIHS study that relied on driver phone records found a four-fold increase in the risk of injury crashes, while a Canadian study found a four-fold increase in the risk of crashes involving property damage. Separate surveys of driver behaviour before and after hand-held phone use bans show reductions in the use of such phones while driving.

The HLDI database doesn’t identify drivers using cellphones when their crashes occur, but 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 the decreasing trend began well before the state’s ban on hand-held phones, and actually based briefly when the ban took effect. Trends in D.C., Connecticut and California did not change.

“So the new findings don’t match what we already know about the risk of phoning and texting while driving,” Lund said. “If crash risk increases with phone use and fewer drivers use phones where it’s illegal to do so, we would expect to see a decrease in crashes. But we aren’t seeing it. Nor do we see collision claim increases before the phone bans took effect. This is surprising too, given what we know about the growing use of cellphones and the risk of phoning while driving. We’re currently gathering data to figure out this mismatch.”

Lund suggested factors that might be eroding the effects of the ban, including drivers switching to hands-free phones, because no U.S. state currently bans all drivers from using such phones. In this case, crashes wouldn’t go down because the risk is about the same, regardless of whether the phones are hand-held or hands-free. “Whatever the reason, the key finding is that crashes aren’t going down where hand-held phone use has been banned,” Lund said. “This finding doesn’t auger well for any safety payoff from all the new laws that ban phone use and texting while driving.”

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