VIENNA, Va. – Companies that strictly enforce bans on cell phone use while driving among employee drivers have lower fleet crash rates that other firms with milder policies, according to a study conducted by the Network of Employers for Traffic Safety.

The study — covering 45 companies, 400,000 vehicles and 8 billion miles traveled — found that companies with the lowest crash rates were most likely to have a total ban on talking and texting while behind the wheel and several were also more likely to terminate a driver for violating the policy.

More than a dozen companies that fell in the bottom of the rankings had some policy against hand-held cell phones in place, but did not terminate a driver for violating the policy.

"This is the first evidence we’ve seen that shows the combination of a strong mobile device policy and strict consequences can result in lower crash rates," said Bill Windsor, NETS Board Chairman. "The benchmark study shows the potential for well-written state laws combined with strong enforcement to eventually reduce crash rates in the general population."

The study contradicts a recent report by the Highway Loss Data Institute in Arlington, Va., that found laws prohibiting drivers from texting while driving do not bringing down crash rates; and, in fact, some crash rates tend to increase after a ban goes into effect.

The conclusions were based on comparisons of claims rates in four states before and after texting bans were enacted.

Proponents of cell phone bans, including U.S. Transportation Secretary Ray Lahood, called that study misleading.