Tuesday, the U.S. Dept. of Transportation banned texting by commercial drivers. The regulatory guidance is published in the January 26 Federal Register and relates to 49 CFR 390.17.
Federal employees are banned from texting by an executive order dated October 1, 2009. The DOT also has a web site called Distraction.gov and a blog called The Fast Lane which have other research on these issues.
Massachusetts has yet to ban texting or cell phone use for all drivers. The Federal ban would apply to all commercial vehicles.