As state legislators across the United States enact laws that ban phoning and/or texting while driving, a new Highway Loss Data Institute study finds no reductions in crashes after hand-held phone bans take effect.
Comparing insurance claims for crash damage in 4 US jurisdictions before and after such bans, the researchers find steady claim rates compared with nearby jurisdictions without such bans. The Highway Loss Data Institute (HLDI) is an affiliate of the Insurance Institute for Highway Safety.
HLDI researchers calculated monthly collision claims per 100 insured vehicle years (a vehicle year is 1 car insured for 1 year, 2 insured for 6 months each, etc.) for vehicles up to 3 years old during the months immediately before and after hand-held phone use was banned while driving in New York (Nov. 2001), the District of Columbia (July 2004), Connecticut (Oct. 2005), and California (July 2008).
Comparable data were collected for nearby jurisdictions without such bans. This method controlled for possible changes in collision claim rates unrelated to the bans — changes in the number of miles driven due to the economy, seasonal changes in driving patterns, etc.
Month-to-month fluctuations in rates of collision claims in jurisdictions with bans didn’t change from before to after the laws were enacted. Nor did the patterns change in comparison with trends in jurisdictions that didn’t have such laws.
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.