There was some good news recently about teens and driving: according to the Centers for Disease Control (CDC), the number of teens who report drinking and driving has come down by half in the past decade from two in ten to one in ten.

While that really is good–great–news, it doesn’t change the fact that motor vehicle crashes are the leading cause of death for US teens. In 2010,  every day seven teens died in motor vehicle crashes–and 770 were treated and released from emergency rooms. If you don’t want this to happen to your teen, it’s important that you know the risk factors for teen crashes–and talk to your child about them.

Drinking. As I said above, the numbers have gotten better here–but still, one in ten is a lot. And even if your teen knows better than to drink and drive, he or she may not always be the one driving. Make it really clear to your teen that drinking and driving are a lethal combination–and that you will always come get them, no matter what, if they find themselves facing that situation.

Speeding. Teens are more likely to speed. You need to talk about this a lot, and have a zero tolerance for it. If you catch them or otherwise find out they’ve been speeding, take the keys away. Teens naturally take risks–their brains are still developing, and they don’t fully understand the consequences of their actions. Sometimes you need to understand things for them.

Being male. Not much you can do about this, but be aware that male teens are more likely to speed and get into accidents than females. I’m usually very much against treating one gender differently, but data is data. Talk a lot to your sons–and make sure your daughter understands this about her male friends (and boyfriends).

Not wearing seat belts. For whatever reason, teens have a tendency to not wear seat belts–in 2011, only half of high-schoolers reported always wearing a seatbelt when driving with someone else. Maybe they just aren’t cool. But cool or uncool, they absolutely save lives–and your teen absolutely needs to wear one. It’s the law here in Massachusetts–they could get their license suspended if they are a junior driver.

Driving together. The risk of fatal crashes goes up the more kids are in the car together. It doesn’t need to be a car full–risks go up when you add even one or two passengers. This will make sense to anyone who has ever watched teens together–they have a way of distracting and goading each other. Driving with a bunch of friends is about the least safe way for a teen to get anywhere. Always know how many people will be in the car.

Distractions. Texting is the one we talk about a lot now–and despite the media coverage, and laws in many states (including Massachusetts), a third of teens still admit to texting while driving.It is not physically possible to look both at the road and your phone. Using your cell phone bill, you should be able to see when your child texts. If you find any when you know he or she was driving, that’s another reason to take the keys away.

It’s not just texting, though. Anything that takes your eyes or attention away from the road can cause a crash. That could be as simple as changing the radio station or turning to talk to a passenger or reaching for a sip of coffee. Anything. Make sure your teen understands this.

Experience. As with anything, practice matters. Teens are most likely to get into accidents in that first year or so after getting their license. So spend a lot of time in the car with your teen. Make sure they get lots of time on the road with you before and after they get their license–don’t just leave it to the Driver’s Ed instructor. When they have their license, start things out gradually. Be sure they are comfortable and capable before you  give them additional privileges.

If you do all this, I can pretty much guarantee that your child will get annoyed, even mad. There will be a whole lot of eye-rolling, a whole lot of I-know-all-this!, and you will be accused of being overly strict and not trusting them. Ignore it. Stand firm.

You may just save their life.

For more information, check out the Teen Drivers page of the CDC website.

Claire McCarthy is a primary care physician and the medical director of Boston Children’s Hospital’s Martha Eliot Health Center.  She blogs at Thriving, the Boston Children’s Hospital blog, Vector, the Boston Children’s Hospital science and clinical innovation blog, and MD Mama at Boston.com.