Do you have the knowledge to be a designated friend? Quiz yourself to find out if you can keep your friend out of harm's way.
Whether you know it or not, you're responsible for recognizing the signs of an impaired driver. According to the National Highway Traffic Safety Administration, the leading cause of teen deaths is injuries from car accidents. Teen drivers are four times more likely to crash than adult drivers are.

A new study suggests that teens may be riskier drivers due to their brain development. The study indicates that the portion of the brain that manages risk isn't fully formed until the age of 25.

Teens are more likely to engage in risky driving-- such as speeding, running red lights, riding with an intoxicated driver and driving while impaired with drugs or alcohol. The Citizens Against Drug Impaired Drivers states prevention is the best solution for impaired driving.

So take our quiz to see if you know when to ask your friend to hand over the keys.

For more information on impaired driving, and how you can stay safe

http://www.channelone.com/news/2004/04/09/dan...

http://www.cdc.gov/ncipc/factsheets/teenmvh.h...

http://www.nhtsa.gov/