If you see a teen driver talking on the phone, it's more likely they're talking to a parent than a buddy, claims new research.

A survey of more than 400 drivers reveals teens are talking while driving because most of the time it's a parent calling and they're afraid not to answer. The survey polled drivers ages 15 to 18 in 31 states.

"Teens said parents expect to be able to reach them, that parents get mad if they don't answer their phone and they have to tell parents where they are," said Noelle LaVoie, PhD, a cognitive psychologist based in Petaluma, California, in a release on the study.

Teens also stated cellphone use while driving is prevalent with parents and  "everyone is doing it," according to the study, funded by the National Institutes of Health.

The National Highway Transportation Safety Administration (NHTSA) claims such distracted driving is a leading cause of car crashes, and accounts for 11 percent of fatal accidents among teen drivers. Of that 11 percent, 21 percent involved cellphone use, states a 2013 report by the NHTSA.

"It's critical to raise awareness among parents and provide teens with tools for communicating with their parents," said study co-author Yi-Ching Lee, PhD, of Children's Hospital of Philadelphia.

A Liberty Mutual survey conduced with the Students Against Destructive Decisions reported 86 percent of eleventh and twelfth graders admit to using a cellphone while driving. That's double the number reported in a 2009 Pew survey.

While teens are more likely talking to parents while driving, if they text it's mostly to friends, notes the survey results

"Parents need to understand that this is not safe and emphasize to their children that it's not normal or acceptable behavior," said LaVoie. "Ask the question, 'Are you driving?' If they are, tell them to call you back or to find a spot to pull over so they can talk."

A Centers for Disease Control fact sheet regarding teen drivers reveals car crashes are the leading cause of death for U.S. teens and that in 2010 seven teens died every day from motor vehicle injuries.