The problem begins at the scene of the crime, says the NSC, where police rely on drivers and witnesses to implicate mobile devices. Witness statements and memories may be inaccurate; furthermore, drivers may be unwilling to convict themselves of careless driving. Police are also more focused on recording obvious violations, like a car veering off a lane or drug impairment, to use in criminal cases rather than underlying the reason for the fatal symptom.

Next, cell phone records can be difficult to obtain from wireless companies, and even if it is relinquished, they must comply with the moment of the crash to be used in court, even if the exact moment is not unknown.

We believe the number of crashes involving cell phone use is much greater than what is being reported,” said Janet Froetscher, president and CEO of the National Safety Council. “Many factors, from drivers not admitting cell phone use, to a lack of consistency in crash reports being used to collect data at the scene, make it very challenging to determine an accurate number.”

There were also questionable disparities among state-by-state reporting, shows the study. In Tennessee, 93 fatal crashes involved cell phones in 2011, while more densely-populated New York reported only one, and while Texas reported 40 instances, nearby Louisiana showed none.

According to the NHTSA, texting while driving is as dangerous as driving after consuming four beers, and causes 1,600,000 accidents per year; 30,000 injuries annually; and 11 teen deaths a day.