NEW YORK – Not that it's too hard to believe, but researchers at Columbia University say that mandatory alcohol testing for truck drivers in the U.S. contributes to a significant reduction in alcohol-involvement in fatal trucking accidents.

Commercial truck drivers with a blood-alcohol content of .04 or higher are subject to immediate suspension. 

To date, the program had not been adequately evaluated, according to J.E. Brady and colleagues at Columbia University. They say, however, that they've been able to determine that mandatory testing was found to be associated with a 23 percent reduction in risk of alcohol involvement in fatal crashes by truck drivers.

In comparison to these low rates across the U.S., neither Canada nor Mexico subject commercial drivers to mandatory testing.

Dr. Guohua Li of Columbia University notes that in both nations, fatal crashes involving commercial drivers appear "much more likely to involve alcohol."

The study, published in the American Journal of Epidemiology, used data from the Fatality Analysis Reporting System (FARS between 1982 and 2006, consisting of nearly 70,000 semi drivers and more than 80,000 other drivers.

Of the more than 66,000 fatal crashes involving more than one vehicle, 2.7 percent of the truckers had positive blood-alcohol concentrations, compared to 19.4 percent of other drivers.

Of course, that could also indicate that professional truck drivers are far more mature and responsible on the road than the average four-wheeler.

Li says the total number of fatal crashes per mile of travel for motor carriers has also decreased significantly since 1995. And the prevalence of alcohol-related fatal crashes among commercial truck drivers is now comparable to commercial pilots.