Yes it is true.  1 in 4 auto accidents are caused by cell phone use based on a study from The National Safety Council's annual injury and fatality report of 2014.  It found that the use of cell phones caused 26% of the nation's car accidents, an increase from the year before.  There have been an estimated 245,358 car crashes involving cell phones. Most of the accidents involved someone using the cell phone while talking on hand held or hand free devices. This report along with a report done by Texas A & M demonstrates that just talking on a phone can be more dangerous than texting and that talk to text may not be a solution.

Cell phone use has an increased reaction time resulting in less chance of avoiding an accident. The NSC report also indicates a slight rise in observed manipulation of hand held devices.  It was estimated that the actual incidence of cell phone use resulting in an accident or a fatality was under reported due to the drivers being unwilling to admit using their phones.  

 Texting itself makes you 23 times more likely to crash and is the same as driving 5 seconds without looking, which is the length of a football field if driving at 55 mph. It slows your brake reaction time by 18% and is the number one driving distraction reported by teen drivers.

National Safety Council Release