Several states have banned talking on hand-held devices and texting while driving, but a recent study on the laws' effect might spark debate over the dangers of engaging in these activities while driving.

A study by the Arlington, Va.-based Highway Loss Data Institute, an affiliate of the Insurance Institute for Highway Safety, examined insurance claims from crashes before and after bans took effect in California, Connecticut, the District of Columbia and New York state and found that claim rates did not go down after those bans were put in place.

Further, the institute found no change in patterns of incidents compared with states that do not ban using cell phones while driving.

“So the new findings don't match what we already know about the risk of phoning and texting while driving,” institute President Adrian Lund said in a statement. “If crash risk increases with phone use and fewer drivers use phones where it's illegal to do so, we 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 cell phones and the risk of phoning and driving,” Mr. Lund said.

Six states, the District of Columbia and the Virgin Islands ban talking on hand-held devices; 19 states, the District of Columbia and Guam ban texting while driving, according to the Governors Highway Safety Assn. The U.S. Department of Transportation also has banned commercial truck and bus drivers from texting while driving.

“We're currently gathering data to figure out this mismatch,” Mr. Lund said.