A recent report by the pro-trucking American Transportation Research Institute featured a lot of good news, including this: The number of fatal crashes involving large trucks dropped from 5,684 in 1979 to 2,987 crashes resulting in 3,380 fatalities in 2009.

Here’s another way of looking at it: They dropped from 2.2 per 100 million vehicle miles traveled (VMT) to fewer than 1.3 from 2000 to 2009.

Big rigs also are causing far less injuries as well as property damage now than they were in the past.

The report, “Predicting Truck Crash Involvement: a 2011 Update,” was prepared by Micah Lueck, ATRI research associate, and Daniel Murray, ATRI vice president of research.

The purpose of the report was to analyze which driver violations and convictions in 2008 were most closely associated with a crash in 2009 and to compare that with a similar report done in 2005.

The most predictive behavior, surprisingly, was a conviction for either failing to use a turn signal or using one improperly, which increased the likelihood of a cash by 96 percent.

Why would such a seemingly minor conviction lead to so many more crashes? Murray said the industry has greatly reduced the number of truly hazardous drivers in recent years. A driver who doesn’t obey such a basic rule as using a turn signal properly, on the other hand, is an accident waiting to happen.

The Federal Motor Carriers Safety Administration recently adopted a new enforcement mechanism, CSA, that better keeps track of company and driver violations. It will make it very difficult for unsafe drivers to job hop from company to company, as they sometimes do now. It’s a headache for companies, but it seems likely to make our highways safer.